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Tibial Shaft Fractures
Introduction
Fractures of the tibial shaft are defined as occurring 5 cm proximal to the tibial plafond and distal to the tibial plateau. The subcutaneous location of the tibia makes it a common site for open fractures and perioperative wound complications. Tibial shaft fractures are more commonly associated with compartment syndrome than any other fracture. Fractures in the proximal and distal thirds of the tibia are commonly associated with malreduction and malunion. These features make the management of tibial fractures a challenge. A wide array of successful treatments for tibial shaft fractures have been described, including casting, functional bracing, plating, intramedullary (IM) nailing, and external fixation. This chapter discusses the various aspects of the treatment of tibial shaft fractures and provides a practical approach to overcoming management obstacles.
After the discussion of tibial shaft fractures, brief sections are included on isolated fractures of the fibular shaft, injuries of the proximal tibiofibular joint, and fatigue fractures of the tibia and fibula.
Relevant Surgical Anatomy
The lower leg, extending from the knee to the ankle, serves as a weight-bearing support for the body. The neurovascular supply of the foot, including the extrinsic myotendinous units, is located throughout the lower leg.
The tibia is asymmetrically surrounded by soft tissues that determine the shape of the lower leg. The tibia has a roughly triangular external cross section with an anteriorly directed apex. Its anteromedial subcutaneous surface has no muscular or ligamentous attachments from the pes anserinus tendons and tibial collateral ligament of the knee proximally to the deltoid ligament of the ankle distally. This readily palpable surface is concave medially as it approaches the medial malleolus. Its anterolateral surface forms the medial wall of the anterior muscular compartment of the leg, with the tibialis anterior and, more distally, the neurovascular bundle and extensor hallucis longus muscles. The tibia's posterior surface, under the superficial and deep muscle compartments, has attachments from proximal to distal of the semimembranosus, popliteus, soleus, tibialis posterior, and flexor digitorum longus muscles. The posterior tibial vessels, the tibial nerve, and the flexor hallucis longus muscle approach the tibia distally, curving around the medial malleolus behind the tibialis posterior and flexor digitorum longus.
The adult tibia ranges from less than 30 cm to more than 47 cm in length and from 8 mm to more than 15 mm in internal midshaft diameter. Most of the tibia is diaphyseal ( Fig. 64.1 ). Its enlarged proximal and distal ends are formed of cancellous bone, which varies in density according to both location and the individual's age and metabolic bone status. The cortex surrounding the metaphyseal spongiosa becomes thin as distance increases from the diaphysis.
The proximal tibial metaphysis, with its medial and lateral tibial plateau, is much larger in diameter than the shaft but is similarly triangular in cross section. Laterally, it overhangs the interosseous membrane and articulates posterolaterally with the head of the fibula. Its anterior apex forms the tibial tubercle where the patellar ligament attaches. Also apparent is apex-anterior angulation of the proximal tibia, averaging 15 degrees. The backward-sloping but variably shaped anterior surface of the tibial metaphysis offers a surface for inserting an IM nail. The cancellous bone of the proximal metaphysis can be perforated to gain access to the medullary canal. However, the shape of the proximal tibia, its posterior overhang, and its thin, flat posterior wall make it possible to err and perforate the posterior cortex.
From 5 to 10 cm distal to the tibial tubercle, the medullary canal becomes distinctly tubular, with thick walls, especially anteriorly, where the prominent crest of the tibia occupies nearly a third of the diameter of the entire bone. It is noteworthy that although the canal is tubular, the shaft of the tibia resembles the shape of a right-angle triangle in cross section, with the lateral and posterior cortices as the sides and the medial cortex (shin) as the hypotenuse of this triangle. The canal is positioned at a right angle or the posterolateral corner of the triangle. This fact is important to remember when inserting IM nails or pins and screws into the tibial shaft. The tibial crest that is palpated in the anterior leg is a lateral structure with the IM canal lying medial to it. The dense cortical bone of the shaft is difficult to pierce and needs a sharp drill, leading to significant heat during penetration. It is essential when placing screws or pins across the tibial diaphysis to remember the thickness of the anterior crest and to aim posteriorly enough to bisect the internal rather than the external diameter and thus obtain bicortical penetration ( Fig. 64.2 ).
Distally the shaft flares and becomes more rounded as it transitions from diaphysis to metaphysis. The cortex thins, and the fatty medullary contents are replaced with cancellous bone that is surprisingly dense, especially in the young and active person. The 5 cm above the subchondral bone of the tibial plafond provides secure purchase for screws and is often compact enough to resist penetration by an IM nail.
The contour of the distal tibia is notable for a pronounced concavity of its anteromedial surface—enough so as to suggest a varus deformity if one looks at the subcutaneous outline rather than the central axis of the bone. Restoring this distal medial concavity is an essential part of closed reduction of distal tibial shaft fractures. If a cast applied to such an injury is straight along its medial side rather than concave over the distal third, a valgus malalignment is produced. Mast and coworkers point out that the shape of the tibia's medial surface is fairly constant from patient to patient. The radius of the supramalleolar curvature is approximately 20 cm. As the triangular diaphyseal cross section rounds gently into the plafond and distal tibial metaphysis, the anteromedial surface, oriented about 45 degrees to the sagittal plane, turns medially so that its most distal extent lies nearly in a sagittal plane. According to Mast and colleagues, the relative constancy of this surface shape permits precontouring of a plate that can be used to reduce a fracture without complete exposure of all its fragments. Medial anatomic plate design takes this anatomic angulation into account.
The tibia's medullary canal extends from the cancellous bone of the proximal metaphysis to that of the distal metaphysis. If the canal were extended proximally along its axis, it would enter just lateral to the middle of the tibial plateau. This is due to the fact that there is relatively greater medial overhang. The largest sagittal dimension of the proximal tibia is also laterally located. Buehler and colleagues pointed out that for both these reasons, a lateral entry site for an IM nail, anterior to the lateral intercondylar eminence, is least likely to deform a proximal fracture. Moreover, because the tibial nail entry is in the anterior aspect of the proximal tibia, the nail should remain in the anterior aspect of the tibia, and the Herzog bend of the nail should be proximal. This avoids anterior angulation of the proximal fragment. The diaphyseal canal is significantly more round in its cross section than the external appearance of the tibia would suggest. Unlike the femur, it is more hourglass-shaped than tubular, with a variably pronounced isthmus. Even after IM reaming, a snug fit for an IM nail is obtainable only in the middle of the tibia. This adversely affects the stability of proximal and distal fractures fixed with a nail if not locked with screws in multiple planes. In a young person, the medullary canal tends to be narrow. With aging and osteoporosis, the cortex becomes thinner, the metaphyseal cancellous bone becomes less dense, and the internal diameter of the medullary canal increases.
The diaphyseal blood supply typically reaches the tibia by way of a single nutrient artery, a proximal branch of the posterior tibial artery. After passing through the most proximal portion of the tibialis posterior, it obliquely enters the tibial shaft on its posterior surface in the proximal portion of the middle third of the bone. It is easily injured by displacement of a fracture through its long cortical foramen. Within the medullary canal, it courses proximally and distally, anastomosing with metaphyseal endosteal vessels ( Fig. 64.3 ). Thus a displaced fracture of the diaphysis is likely to devascularize the shaft downstream from the nutrient artery. If peripheral soft tissues are also significantly stripped, the entire vascular supply can be lost over a distance of several centimeters. The combined loss of medullary and periosteal blood supply with marked displacement and bone loss interferes with fracture healing and presents the risk of nonunion and posttraumatic osteomyelitis.
Through its intraosseous distribution, the medullary arterial system of the tibia provides nourishment to the majority of the uninjured diaphysis. Only the peripheral one-fourth to one-third of the diaphyseal cortex is supplied by anastomosing periosteal vessels. This fact is of special significance after reaming for an IM nail because the combined devascularization caused by both fracture and reaming produces a layer of necrotic bone through much of the diaphysis. Reaming stimulates inflammation, and the medullary arterial circulation regenerates in a few weeks. This permits revascularization of the inner cortical bone, which is also supported by recruitment of periosteal collateral circulation if the surrounding soft tissues are healthy enough. However, until revascularization has occurred, the cortical bone is not able to participate in the healing process or resist infection.
After a fracture, the tibial blood supply changes dramatically. Peripheral vessels are recruited to take over much of the arterial supply of the cortex and revascularize necrotic areas as well as provide nourishment for the metabolically active peripheral callus. This process requires healthy surrounding tissues and is most effective in areas with muscles closely applied to the tibia. Those surfaces covered only with periosteum, subcutaneous tissue, and skin are less able to benefit from this temporary extraosseous blood supply. Thus viable attached muscular pedicles are crucial for segments of a fractured tibia and should be preserved during surgical exposure for débridement or fixation.
A most important feature of the lower extremity anatomy is the relationship between the tibia and the smaller fibula, which is situated posterolaterally and is surrounded by muscle. The fibula articulates with the tibia proximally and distally. Proximally, the fibula articulates with the tibia posterolaterally. Distally, the tibia lies within a shallow articular facet (incisura) on the posterolateral surface of the distal tibial metaphysis.
The subcutaneous fibular head anchors the lateral collateral ligament of the knee and the biceps femoris tendon. The common peroneal nerve wraps superficially around the fibular neck from an initially posterior location and divides into superficial and deep portions. The peroneal nerve is at risk of injury from direct blows; from the stretching that occurs with widely displaced fractures or dislocations; from posterolateral surgical approaches to the knee; and importantly, from the pressure of casts, splints, and even firm mattresses.
Although the fibula does bear a small portion of body weight, function is only slightly affected by the absence of its diaphysis or proximal extent. Removal of a portion of the fibula decreases but does not abolish tension strain on the tibia's anterior surfaces. The fibular shaft is important for the origin of muscles. The fibula is accompanied by the peroneal artery. The combination of artery and bone can be surgically transferred as a free or pedicle graft to treat bone defects.
The distal end of the fibula, or lateral malleolus, has a major role in the structural integrity of the ankle joint. It is securely attached to the distal tibia through the ligaments of the ankle syndesmosis. Disruption of these ligaments, with resultant loss of fibular support for the talus, may occur in association with tibial shaft fractures; therefore the integrity of the ankle joint should always be assessed in patients with tibial fractures.
A thick interosseous membrane connects the lateral crest of the tibia to the anteromedial border of the fibula. Its major fibers run downward and laterally. This membrane is often largely intact after indirect torsional fractures of the tibia, and according to Sarmiento and Latta, it is the major limit to shortening of such injuries. Over the top of the interosseous membrane, beneath the proximal tibiofibular joint, the anterior tibial artery and its accompanying veins enter the anterior compartment of the leg. Injury to these structures may be associated with proximal tibial fractures and tibiofibular joint dislocations. Posterior to the distal edge of the interosseous membrane, the terminal peroneal artery passes anteriorly to join the vascular anastomoses about the ankle.
The tibia and fibula are surrounded by limited soft tissue structures that are most important in injuries to this region. When the fibula and/or tibia are fractured, surgeons must assess and give attention to the soft tissues and bones to avoid irretrievable errors. Open wounds are usually obvious, although they may be small and underrepresent the extent of internal damage. Subcutaneous degloving can result in extensive muscular, fascial, and skin necrosis even if initially appearing benign. Swelling within the fascial compartments of the leg may gradually cause tissue pressures high enough to produce compartment syndrome. Direct or indirect injuries may occur to the nerves and blood vessels of the leg. Clearly, each anatomic element of the leg must be considered together with injuries to its bones and joints.
The skin receives significant blood supply from the underlying fascia by way of small perforating arteries. These are disrupted by subcutaneous dissection or degloving injuries, which separate the subcutaneous fat from the underlying fascia. Therefore surgical dissection should proceed beneath, rather than superficial to, the deep fascia so as to decrease the risk of skin necrosis. This approach will also take advantage of the subfascial arterial plexus, which is raised off the underlying muscle with the fascia. The dermal plexus is the terminal vascular bed of the skin. Its patency and perfusion are demonstrated clearly by punctate bleeding after tangential excision of a split-thickness layer of skin.
Superficial veins in the subcutaneous tissue of the leg include the saphenous on the medial side and the short saphenous on the lateral side. The small saphenous nerve branches run with the saphenous vein, and the sural nerve runs with the short saphenous vein. These nerves can be entrapped in a scar or suture, resulting in painful neuromas. Because the deep venous system may be damaged at the time of injury or occluded by venous thrombosis, it is important to preserve the major superficial veins. Note that the saphenous vein is subcutaneous. It is found anterior to the medial malleolus and then medially and posterior to the tibia at the distal one-third of the bone.
The deep fascia of the leg envelops all of the muscles circumferentially. It is adherent to the tibia anteromedially in the diaphysis and proximally and distally except for narrow passages for tendons and neurovascular structures. This fascial cylinder is subdivided into four well-defined longitudinal compartments by septa that attach to the fibula. An anterolateral septum divides the lateral compartment from the anterior. A posterolateral septum lies between the lateral and superficial posterior compartments. Finally, a posterior septum intervenes between the deep and superficial posterior compartments. More proximally, this attaches to the medial tibia. Beyond the midshaft, it attaches to the medial surface of the deep investing fascia so that only a small part of the medial surface of the deep posterior compartment, behind the posteromedial border of the distal half of the tibia, is subcutaneous.
Familiarity with the cross-sectional anatomy of the leg is essential for the fracture surgeon. It aids the physical examination, facilitates surgical approaches, and helps avoid injury to neurovascular and tendinous structures during insertion of percutaneous pins and wires ( Fig. 64.4 ).
Key Points: Anatomy
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The backward-sloping anterior surface of the tibial metaphysis offers a surface for inserting an IM nail. The cancellous bone of the proximal metaphysis can be perforated to gain access to the medullary canal. However, the shape of the proximal tibia, its posterior overhang, and its thin, flat posterior wall make it possible to err and perforate the posterior cortex.
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A lateral entry site for an IM nail, anterior to the lateral intercondylar eminence, is least likely to deform a proximal fracture. Because the tibial nail entry is in the anterior aspect of the proximal tibia, the nail should remain in the anterior aspect of the tibia. The Herzog bend of the nail should be proximal. This avoids anterior angulation of the proximal fragment in proximal fractures. The canal is positioned at a right angle or the posterolateral corner of the triangle.
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The dense cortical bone of the shaft is difficult to pierce and needs a sharp drill, leading to significant heat during penetration.
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It is essential when placing screws or pins across the tibial diaphysis to remember the thickness of the anterior crest and to aim posteriorly enough to bisect the internal rather than the external diameter and thus obtain bicortical penetration.
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The 5 cm above the subchondral bone of the tibial plafond provides secure purchase for screws and is often compact enough in non-osteoporotic bone to resist penetration by an IM nail.
Compartmental Anatomy
The anterior compartment contains the dorsiflexors of the ankle and toes: the tibialis anterior, extensor hallucis longus (in its distal half), and extensor digitorum communis with accompanying peroneus tertius. Its neurovascular bundle consists of the anterior tibial artery and veins, joined in the proximal part of the compartment by the deep peroneal nerve. The artery is assessed distally by the dorsalis pedis pulse. However, flow may be retrograde from the deep plantar arch and thus may be present in spite of anterior tibial artery loss. The deep peroneal nerve supplies an autonomous sensory zone dorsally on the foot between the bases of the first and second toes. It provides motor control for the anterior compartment muscles as well as the short toe extensors. During most of its course through the anterior compartment, the neurovascular bundle lies deep on the interosseous membrane lateral to the tibialis anterior. However, as this muscle becomes tendinous and thinner in the proximal third of the distal quarter, the neurovascular bundle advances anteriorly across the lateral surface of the tibia, where it may be harmed by pins inserted through the bone. A little more distally, it lies anteriorly on the tibia between the tendons of the tibialis anterior and extensor hallucis muscles.
The lateral compartment, superficial to the fibula, contains the peroneus brevis and longus muscles, the evertors of the foot. The peroneus longus begins proximally on the lateral aspect of the fibular head. The common peroneal nerve passes under this muscle, where it covers the neck of the fibula. Proximally, the peroneus brevis is deep to the longus until, distally, it becomes anterior. Thus behind the lateral malleolus, the brevis is the anterior of the two tendons. The superficial peroneal nerve, which provides sensory input from the remainder of the dorsum of the foot and motor function to the peronei, lies within the lateral compartment, but no major vascular structures are present.
The superficial posterior compartment contains the triceps surae, or primary ankle flexors, gastrocnemius, soleus, and plantaris muscles. The sural nerve lies between layers of the posterior fascia of this compartment and provides sensation to the lateral heel. No major artery lies within this compartment, which is the most distensible and least likely to develop elevated pressures after injury.
The deep posterior compartment lies underneath (anterior to) the superficial compartment and distal to the popliteal line, with its muscles applied to the posterior surfaces of the tibia, interosseous membrane, and fibula. Within it lies the posterior tibial vessels and the tibial nerve, which provides motor function to the compartmental muscles and the plantar intrinsic muscles and sensory input from the sole of the foot. Also present are the peroneal vessels. The deep posterior compartment muscles are the flexor digitorum longus medially, the flexor hallucis longus laterally, and deep to these, the tibialis posterior. From proximal to distal, the tibial neurovascular bundle first lies posterior to the popliteus and then posterior to the medial border of the tibialis posterior. The tibial nutrient artery leaves the posterior tibial shortly after it is formed and reaches the bone through the proximal part of the tibialis posterior. The tendon of the tibialis posterior passes across the tibia and under the flexor digitorum longus to lie anterior to it and establishes the well-known relationship of the deep posterior compartment structures behind the medial malleolus: tibialis posterior, flexor digitorum longus, posterior tibial artery and tibial nerve, and flexor hallucis longus—“Tom, Dick, and Harry” ( Table 64.1 ).
Table 64.1
Tests for Assessment of Peripheral Nerves and Compartments of the Leg a
| Nerve | Compartment | Motor Function | Sensory Function |
|---|---|---|---|
| Deep peroneal | Anterior | Toe dorsiflexion | Dorsal I–II web space |
| Superficial peroneal | Lateral | Foot eversion | Lateral dorsum of foot |
| Tibial | Deep posterior | Toe plantar flexion | Sole of foot |
| Sural | Superficial posterior | Gastrosoleus | Lateral heel |
a By testing each nerve and associated muscle group, it is possible to assess the status of myoneural tissue within each compartment.
Mechanism of Injury and Biomechanics
Tibial shaft fractures are caused by both high- and low-energy mechanisms. Injury mechanisms may be varied depending on urban, suburban, or rural location. In a study reviewing 523 consecutive tibial fractures, the mechanisms of injury were fall (17.8%), fall from stairs (2.5%), fall from height (6.2%), sports (30.9%), blow/assault (4.5%), and road traffic accidents (37.5%). Of the road traffic accidents, 59.2% were pedestrians struck by motorized vehicles. Motorcyclists were twice as likely to have an open fracture compared with pedestrians and motor vehicle passengers or drivers. Gunshot wounds to the tibia can be either low velocity (<2000 feet per second), as typically seen in the civilian population, or high velocity (>2000 feet per second), as seen more frequently in the military population. The amount of soft tissue injury associated with the fractures is increased in high-velocity injuries, leading some authors to classify all high-velocity gunshot wounds to the tibia as a Gustilo type III open fracture. High-velocity fractures more commonly occur in younger patients involved in road traffic accidents or a fall from height. Low-energy mechanisms are also commonly associated with tibial shaft fractures. The most common tibial fractures caused by sports injuries result from a direct blow while playing soccer. Direct blows to the tibial shaft by a car bumper, football cleat, or a baseball bat, for example, cause a blunt crush injury to the muscles of the leg and are associated with a high incidence of compartment syndrome. A crush injury mechanism implies a severe soft tissue injury regardless of the fracture pattern and carries with it a potential for poor prognosis. Tibial shaft fractures caused by repetitive normal loading are termed fatigue or stress fractures and are discussed separately at the end of this chapter.
The tibia is subjected to compressive, tensile, and torsional forces during normal activity. As with other long bone fractures, bending forces tend to produce transverse fractures with a possibility of a “butterfly” or wedge fragment of various sizes on the compression side. Oblique fractures are also caused by lateral bending force where the edge fragment remains attached to one of the main fragments. When nailing oblique fractures, the surgeon should be mindful to the possibility of a wedge fragment being dislodged. Spiral fractures are caused by an indirect torsional force. They are often the result of low-energy mechanisms. Various fracture patterns can result from the combination of bending, torsion, and axial forces. The extensor mechanism of the knee, with its patella tendon attachment to the tibial tuberosity, is the main deforming force acting to extend the proximal tibia and should be considered during fracture reduction and fixation. As with all fractures, the treatment strategy is based on surgeon preference, mechanism of injury, soft tissue disruption, and fracture pattern.
Diagnosis
History
A detailed history should be obtained from the patient or a reliable witness. The mechanism of injury, site of injury, estimated level of energy, and time from injury to presentation should be determined. Mechanism of injury can influence the fracture pattern and associated injuries. Certain locales (e.g., barnyards and swamps) are notorious for the presence of virulent microorganisms that may increase the infection rates in open tibial fractures. High-energy multifragmentary fractures suggest the potential for soft tissue complications. A low-energy mechanism coupled with a high-energy fracture pattern may suggest a pathologic fracture mechanism. Time from injury to presentation can give valuable information on the overall patient status, blood loss, and advancement of myonecrosis in an ischemic limb. The patient's age, comorbidities, and general profile (occupation, social history, drug use, smoking status, activity levels, expectations) should also be assessed. The patient's age may decrease bone quality, bone healing, and activity level. Comorbidities, such as peripheral vascular disease and diabetes, may decrease bone and soft tissue healing as well as increase the potential for infection. History of human immunodeficiency virus (HIV) and bleeding disorders may also increase the risk for infection and postoperative complications. Tibial fracture in the setting of a patient who smokes tobacco is associated with poor wound and fracture healing. Finally, the patient's activity profile may influence treatment decisions. A simple low-energy pattern in a young athlete may be treated differently from that in a sedentary elderly person with severe comorbidities.
Examination
A general examination of the patient for additional injuries is performed in accordance with the injury mechanism and according to the guidelines of the American College of Surgeons Advanced Trauma Life Support (ATLS) system. The injured limb is then examined in a goal-directed, systematic fashion for vascular injury, neurologic injury, soft tissue injury, compartment syndrome, and ipsilateral limb injuries. All aspects of the physical examination should be thoroughly documented because they may change during the course of treatment.
Proximal tibia fractures may be associated with anterior tibial artery injury where it passes through the interosseous membrane. The dorsalis pedis and posterior tibial pulses must be checked and documented. Distal perfusion is assessed primarily by pulses, but also by skin color, warmth, and capillary filling. If there is any question about the adequacy of perfusion, the fracture should be reduced and splinted, and perfusion should be reassessed. The ankle-brachial index (ABI) can also be used to assess the isometricity of the perfusion to the limb. If the fracture is distal, the toe-brachial index can also be used to assess vascular injury. In a patient with no vascular disease, an ABI of 0.9 or higher is within normal limits. Any patient with an ABI of less than 0.9 should have a further assessment of the vascular tree to rule out a vascular injury. Doppler-assisted pulse measurements are useful adjuncts to the physical examination. Absent pulses in the initial examination warrant a vascular surgeon consult and psossibly angiography. However, this should not delay emergent orthopaedic treatment because it is often the case that after warming the leg and stabilizing the fractures in the operating room, peripheral pulses return and leg perfusion is restored.
Direct nerve injury is uncommon in closed fractures with the exception of peroneal nerve injury in fibular neck fractures. Neurologic function is assessed by specific tests for movement and sensation of the nerves of the lower leg. Because these nerves travel within different deep fascial compartments, distal neurologic testing is valuable for identifying neurologic deficits of the leg. Sensation is assessed with light touch or pain (e.g., a pin stick) and compared with the contralateral side. Motor function should be tested with formal manual motor tests that require the patient to demonstrate maximal power against the examiner's hand. Strength is then graded from 0 to 5.
The deep peroneal nerve lies in the anterior compartment of the leg. Its sensory innervation is the dorsal first web space between the first and second toes, and its motor test is toe dorsiflexion. The superficial peroneal nerve, which travels through the lateral compartment of the leg, divides approximately 4 cm proximal to the tibial plafond into the medial and intermediate cutaneous branches of the superficial peroneal nerve. The distal ends of these nerves confer sensation of the dorsum of the foot, except for the first web space, and motor activity to the foot evertors. The tibial nerve travels through the deep posterior compartment of the leg. Its sensory innervation is the plantar aspect of the foot. Its motor innervation is the toe plantar flexors. The sural nerve is within the superficial posterior compartment of the leg and provides sensory innervation of the lateral heel but no motor activity. An adequate neurologic examination of a limb with a tibial fracture includes testing and recording the responses of each of the aforementioned nerves. A well-padded splint may then be applied. Access to the foot must be preserved so that a complete examination can be repeated periodically. This can be achieved by removing the cast or splint from the dorsum of the foot and trimming or windowing over the posteromedial aspect to palpate the posterior tibial pulse if needed. Motor function of the deep peroneal and tibial nerves should be assessed with the understanding that assessment is often limited by pain. Paralysis and loss of sensation are often associated with either stretch, direct trauma, or ischemia and should warrant further examination to evaluate for a vascular injury.
The soft tissue assessment is primarily performed during the initial assessment and in the operating room. Before surgery, evaluation of open wounds and grading of open fractures is not as reliable as during and after surgery. The size of the wound and bony defect can increase after surgical débridement, changing the grading of an open fracture. Further exploration of the wound in the emergency department may increase the rate of infection. In a closed injury, the surgeon should circumferentially inspect the limb for wounds. A small wound extending through the dermis should be assumed to communicate with the fracture. The true severity of the fracture can be easily underestimated at this point and should only be determined after surgery.
Compartment syndromes are initially characterized by pain and swelling. Loss of neurologic function, pulses, and skin perfusion is usually not present until later in the course of compartment syndrome. Manual palpation of the compartments has poor diagnostic value in assessing for compartment syndrome. In a conscious patient, pain elicited by passive stretching of a muscle within the compartment can support the diagnosis of compartment syndrome (e.g., anterior compartment pain is produced by passively plantar flexing the patient's toes, and deep posterior compartment pain is assessed by passive toe dorsiflexion), but it is often difficult to separate compartment pressure pain from expected fracture-related pain. Pain by itself is also subjective. Repeated clinical examinations (frequent examinations during the first 24 to 48 hours) and thorough documentation of the physical examinations are the only ways to detect an elevation in compartment pressures and development of compartment syndrome. The increased use of analgesics should be monitored because it may also be associated with increased leg compartment pressures. In the patient who is unconscious or insensate, physical examination may be unreliable, necessitating the use of repeated or continuous direct intracompartment pressure measurements to detect trends in compartment pressure elevations and the development of compartment syndrome. A detailed description of the diagnosis and management of compartment syndrome is offered in a previous chapter in this text.
An ipsilateral fibular fracture is the most common injury associated with a tibial shaft fracture. Other associated injuries are disruption of the proximal and distal tibiofibular joints, extension of the fracture to the proximal and distal articular surface, ligamentous injuries (or dislocations) of the knee and the ankle, femoral shaft fractures (floating knee injuries), and foot injuries. The surgeon should not be distracted by an obvious open tibia fracture and spend sufficient time questioning the patient and examining the whole patient for other injuries. The most frequently missed injuries are in the hands and feet. These should be assessed and reassessed frequently.
Imaging
Examination of the anterior-posterior (AP) and lateral radiographs of the whole tibia is standard in the evaluation of the suspected tibial fracture and helps with the preoperative plan. The radiographs should also be used to determine bone quality and bone loss. AP and lateral radiographs of the knee and ankle should be obtained to assess for additional injuries and possible extension into the proximal and distal tibial articular surface. If articular extension of the fracture is suspected, computed tomography (CT) scans of the joint can help determine whether the treatment should be changed from the initial radiographic assessment. CT scans can help in (1) detecting minimally displaced fractures, (2) better understanding complex fracture patterns, and (3) planning the surgical approach. CT angiography or formal angiography of the leg should be considered when vascular injury is suspected. However, if the zones of boney, soft tissue, and vascular injury are obvious, one should avoid time-consuming studies in the radiology suite that may delay revascularization before irreversible tissue necrosis occurs. A detailed explanation of the judicial use of angiography is available in a previous chapter in this text.
Classification
Tibial shaft fractures are associated with more complications and treatment controversies than any other long bone fracture. Many classifications of tibial shaft fractures have been proposed, but none has gained wide clinical acceptance. For clinical purposes, it is useful to classify and describe a tibial fracture according to (1) the condition of covering tissue of skin and fascia, muscle, tendon, and nerves; (3) fracture location and degree of comminution; (4) associated fibula fracture; (5) articular extension; and (6) localized patient comorbidities. For open fractures, the Gustilo-Anderson classification has been used most frequently to describe the soft tissue envelope. The Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) comprehensive classification for long bones has been used to describe the tibia fracture pattern and for purposes of documentation and research.
Ellis, in 1958, used displacement, comminution, and wound severity to assign tibial shaft fractures to one of three grades: minor, moderate, and major. “Minor” tibial fractures were undisplaced or had only angular deformity; an open wound, if present, was small, and comminution was either absent or minimal. Ellis defined “moderate” fractures as those with complete displacement but with no more than a minor wound or minor comminution. “Major” tibial fractures included all those with significant comminution or a major open wound. Ellis reviewed 343 conservatively treated tibial fractures and found that average healing times were 10 weeks for minor injuries, 15 weeks for moderate injuries, and 23 weeks for major injuries. Delayed union (20 weeks) occurred in 2% of minor, 11% of moderate, and 60% of major fractures. Bauer and colleagues and Edwards noted that the type of trauma (direct or high-energy vs. indirect or low-energy) had a significant effect on outcome and related this to the extent of soft tissue damage. They suggested that the prognosis in fractures of the shaft of the tibia was related more to the severity of soft tissue damage than to the bone injury ( Table 64.2 ).
Table 64.2
Edwards's Classification System for Results After Tibial Fracture Treatment
From Edwards P. Fracture of the shaft of the tibia: 492 consecutive cases in adults. Importance of soft tissue injury. Acta Orthop Scand Suppl. 1965;76:33.
| Good | Fair | Poor a | |
|---|---|---|---|
| 1. Pain | Little or none | Slight | Severe |
| 2. Work capacity | Normal | Difficulty or inability to do heavy work | Markedly decreased, light seated work only |
| 3. Limp | None | Slight with or after severe exercise | Constant |
| 4. Sports activity | Normal | Decreased ability | Short walks only |
| 5. Knee motion | Stable, full extension, loss of flexion <20 degrees | Stable, full extension, flexion to at least 90 degrees | Lack of full extension, flexion to <90 degrees |
| 6. Ankle motion | Less than 10 degrees loss of dorsiflexion, <20 degrees loss of plantar flexion | Dorsiflexion >90 degrees, <30 degrees loss of plantar flexion | Dorsiflexion <90 degrees, >30 degrees loss of plantar flexion |
| 7. Foot motion | Less than 25% decrease of pronation and supination | Moderately decreased | Severely decreased |
| 8. Swelling of lower part of leg | Slight, only after exercise | Slight | Constant |
a Poor results also include (1) amputation, (2) osteomyelitis with recurrent drainage, and (3) pseudarthrosis.
There is a close relationship between wound severity and complications such as infection, delayed union or nonunion, and amputation. Early open-wound classification systems focused on the size of the skin wound. However, the extent of muscle necrosis, microvascular and macrovascular damage, and periosteal stripping are of greater significance. Gustilo and Anderson developed the classification system that is used by most North American orthopaedic surgeons. Its initial three categories were expanded to five, and their specifications were refined to emphasize the importance of the entire wound. According to their original article, open fractures were classified as follows:
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Type I—An open fracture with a wound less than 1 cm long and clean.
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Type II—An open fracture with a laceration more than 1 cm long without extensive soft tissue damage, flaps, or avulsions.
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Type III—Either an open segmental fracture, an open fracture with extensive soft tissue damage, or a traumatic amputation.
Special categories in type III are gunshot injuries, any open fracture caused by a farm injury, and any open fracture with accompanying vascular injury requiring repair. Gustilo and colleagues later specified that open fractures resulting from high-energy or high-velocity trauma, with segmental fractures or severe comminution, should be classified as type III injuries, regardless of the size of the wound.
Because type III itself represents a considerable spectrum of severity, it was necessary to divide these injuries into three very different subtypes :
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Type IIIA—The open fracture involves extensive soft tissue damage, often due to a high-energy injury with a severe crushing component. Massively contaminated wounds and severely comminuted or segmental fractures are included in this subtype. Soft tissue coverage of the bone is adequate.
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Type IIIB—An open fracture with extensive soft tissue damage, periosteal stripping, and bone exposure, usually with severe contamination and bone comminution. Flap coverage is required to provide soft tissue coverage.
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Type IIIC—This fracture is associated with an arterial injury requiring repair.
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This Gustilo-Anderson system is highly predictive of wound infection risk. Infection rates with adequate management have been up to 2% for type I, 2% to 10% for type II, 10% to 50% for type III, and 25% to 50% for type IIIC.
Interobserver agreement in grading open tibial fractures according to Gustilo and colleagues’ classification was investigated by Brumback and Jones. They found that there was approximately 60% agreement in the grading of individual fractures from videotapes of the initial débridement and radiographs. However, the consensus was better regarding the most severe or most minor open fractures. This variation in grading should be kept in mind by the surgeon who wishes to compare the results of different research studies from different institutions.
The classification developed by Johner and Wruhs, later adopted by Müller and associates and the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF) techniques, and subsequently by the Orthopaedic Trauma Association (OTA), is now the most commonly used classification system for scientific studies of tibia shaft fractures ( Fig. 64.5 , Table 64.3 ).
Table 64.3
Johner and Wruhs's Criteria for Evaluation of Final Results After Tibial Shaft Fracture
From Johner R, Wruhs O. Classification of tibial shaft fractures and correlation with results after rigid internal fixation. Clin Orthop . 1983;178:12.
| Excellent (Left = Right) | Good | Fair | Poor | |
|---|---|---|---|---|
| Nonunion, osteitis, amputation | None | None | None | Yes |
| Neurovascular disturbances | None | Minimal | Moderate | Severe |
| Deformity | ||||
| Varus/valgus | None | 2–5 degrees | 6–10 degrees | >10 degrees |
| Anteversion/recurvation | 0–5 degrees | 6–10 degrees | 11–20 degrees | >20 degrees |
| Rotation | 0–5 degrees | 6–10 degrees | 11–20 degrees | >20 degrees |
| Shortening | 0–5 mm | 6–10 mm | 11–20 mm | >20 mm |
| Mobility | ||||
| Knee | Normal | >80% | >75% | <75% |
| Ankle | Normal | >75% | >50% | <50% |
| Subtalar joint | >75% | >50% | <50% | – |
| Pain | None | Occasional | Moderate | Severe |
| Gait | Normal | Normal | Insignificant limp | Significant limp |
| Strenuous activities | Possible | Limited | Severely limited | Impossible |
Although the results of this classification correlate moderately well with outcome, factors other than fracture pattern are also important, including fracture displacement, the severity of soft tissue injury, and the location of the fracture within the tibial shaft. Proximal and distal fractures, which can encroach on the knee or ankle and can complicate the use of intramedullary nailing (IMN), may deserve recognition as a separate category of injury. The poor correlation between functional outcome and the AO/OTA classification has been shown by Swiontkowski and colleagues. Six- and 12-month functional outcomes were measured in 200 patients with unilateral and isolated lower extremity fractures. Patients with C-type fractures had significantly worse functional performance and impairment compared with patients with B-type fractures but were not significantly different from patients with A-type fractures. Gaston and colleagues compared the predictive value of four different classification systems, namely, the AO classification system, the Gustilo classification of open fractures, the Tscherne grading system of closed fractures, and the Winquist-Hansen classification of comminution. The Tscherne classification was the only classification found to correlate to some aspects of functional outcome (the time taken to regain function, with 6 of the 12 functional measurements). However, the surgeon using the Tscherne classification found it difficult to assess soft tissue damage in a closed fracture and, in reality, based his classification on the radiographic appearance of the fracture. This led the authors to conclude that the combined predictive value of these classifications for functional outcome is as good as “the interpretation of the radiographs by an experienced surgeon.”
Another useful classification is the Ganga hospital open injury severity score that is focused on Gustilo and Anderson IIIB open tibia fractures.
This classification was based on a prospective study of 96 consecutive grade IIIB open tibia fractures with 3- to 5-year follow-up. The patient's injury was scored from 1 to 5 on three components of the limb assessment, with the addition of comorbid conditions. The three components were covering tissues (skin and fascia), functional tissues (muscle, tendon, and nerve), and skeletal structures (bone and joints). The intraobserver agreement by 10 surgeons was more than 95%. Future studies are needed to assess the positive and negative predictive value of this classification system.
Key Points: Diagnosis
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The injured limb is examined in a goal-directed, systematic fashion for vascular injury, neurologic injury, soft tissue injury, compartment syndrome, and ipsilateral limb injuries.
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The most common classification for open fractures is the Gustilo-Anderson system, which is highly predictive of the risk of wound infection.
Management
The objective of tibial shaft fracture management is a healed fracture with restored limb function. Treatment decisions should be based on an understanding of the natural history of the injury and the necessary alterations in treatment to accommodate the specific “personality” of the fracture. If no clear indication for surgery exists, the surgeon should proceed with nonoperative management.
Evolution of Treatment
The history of management of severe wounds has, in large part, been the history of open tibial fracture care.
Watson-Jones, the British surgeon and teacher, had an overwhelming influence on fracture treatment throughout the English-speaking world during the latter half of the 20th century. He, and his associate Coltart, believed that “nonunion is never inevitable and that every fracture will unite if it is immobilized long enough.” They recommended immediate anatomic reduction and absolute immobilization in a long leg, non–weight-bearing plaster cast until union was secure.
More recent approaches for treating tibial shaft fractures emphasize (1) categorization according to severity; (2) nonoperative management of less severe injuries; (3) adequate, meticulous, and aggressive débridement of necrotic and contaminated tissue in open fractures; (4) early skeletal stabilization with IMN or an external fixator; (5) early soft tissue repair or closure for severe open injuries; (6) minimally traumatic but mechanically sound internal fixation for unstable fractures; (7) early bone grafting of severe injuries with a high risk of healing problems; and (8) early knee and ankle joint motion to avoid joint stiffness.
Emergent Treatment
The first priority for a patient with a tibial shaft fracture is a thorough, systematic search for other life-threatening injuries, as described in a previous chapter. The surgeon must identify and treat limb-threatening injuries—arterial trauma, compartment syndrome, and open fractures, which can be life-threatening as well. Frequent reassessment, as taught by the ATLS program for the patient as a whole, is equally important for the injured limb to avoid missing a delayed neurovascular catastrophe. The tertiary survey after 24 hours in the awake, alert patient is essential to avoid missed injuries. In the obtunded patient, a secondary survey is performed 24 hours after injury, and then the tertiary survey is performed after the patient is awake and alert.
Initial Care: Immobilization
After an initial evaluation of the injured patient and the injured limb, the surgeon's task is to develop a treatment plan that is appropriate for the injury, the patient, and the available treatment resources. Questions that must be considered are as follows: Is there a life-threatening or limb-threatening injury that must be addressed emergently? Will the evaluating surgeon be the patient's definitive caregiver, or will a transfer of care occur? Is it possible to make a decision regarding definitive care, or should definitive treatment be deferred until more information is gathered from the evaluation of other conditions or consultations? Do the necessary resources exist at the current location to take care of the patient definitively? Has a discussion with the patient, family, or other caregiver been performed to consider the various options? No matter what situation, it is appropriate to provisionally align the fractured leg and immobilize for transfer of the patient in or out of the hospital.
A splint is the preferred immobilization method at this stage. The splint must fit safely, have sufficient padding near bony prominences (patella, fibular head, medial and lateral malleoli, heel, metatarsal heads), support effectively, allow for neurovascular examinations, and be easy to apply by the treating team. It should extend from the mid-thigh to the metatarsal heads. Padding is essential to avoid skin breakdown and to accommodate swelling. The leg is realigned with manual traction and support and placed into or onto the splint, which is then secured to the limb. The knee is kept in extension or slight flexion, and the foot is placed plantigrade. The leg is examined frequently to make sure that the splint does not become too tight and is loosened as needed. The splint should be placed to allow access to anterior compartment pressure measurements and distal pulse measurements. In low-velocity injuries with minimal swelling, it may be possible to place a well-padded bivalved cast initially and then cut out its anterior surface and an area around the medial malleolus to allow for measurement of the posterior tibial pulse ( Fig. 64.6 ). However, there should be a low threshold for removing the cast and examining the patient if there is increasing pain or any change in the examination.
Tibial Shaft Fractures With Associated Arterial Injury
Tibial fractures with associated arterial injuries can have a poor prognosis. If tissue ischemia is present, prompt successful vascular repair will give the best chance of limb salvage. Arterial insufficiency in association with a tibia fracture at presentation requires immediate provisional reduction and splinting. The limb is then reassessed for palpable pulses. If pulses are still not palpable, it may be possible to measure arterial flow at the ankle using Doppler ultrasonography. If perfusion is restored by such a reduction, caution remains advisable because an arterial injury with potential for delayed occlusion may still exist. The ABI is measured. A value of less than 0.9 is abnormal in patients with no peripheral vascular disease. An arteriogram should be considered, and vascular surgical consultation should be obtained if the ABI is less than 0.09 or there is any clinical suspicion of vascular injury. If reduction and splinting do not immediately restore adequate blood flow, then vascular surgery is required if the leg is to be saved, and a vascular surgery consult should be sought emergently. Arteriography may be considered if the location of injury to the vessel is not known. Such a study may be helpful if it can be performed without excessive delay. It is preferred that the patient is taken directly to the operating room for exploration and arterial repair. Amputation is also an option that must be discussed with the patient if satisfactory reconstruction may not be possible or contraindicated.
Limb-threatening arterial injuries associated with tibial fractures occur relatively rarely, making it difficult to create a prospective randomized study for an evidence-based standardized protocol for collaborative management by vascular and orthopaedic surgeons. A patient with a tibial fracture and an arterial injury that causes limb-threatening ischemia is a candidate for arterial reconstruction if flow can be restored within 6 to 8 hours after injury; if there is no anatomic loss of the tibial nerve, which provides sensation to the sole of the foot; and if salvage of a useful limb is possible without compromising the patient's overall condition.
An effective collaborative recommended approach may be as follows: Both legs are prepared and draped to include the pelvis, and both vascular and orthopaedic teams work together to rapidly assess the injured leg. The decision to revascularize instead of amputate is crucial. Generally, this choice involves exploring the injured vessels. If revascularization is chosen, it must be accomplished as rapidly as possible. Initially, a temporary vascular shunt is placed to restore blood flow. The orthopaedic team then applies an external fixator to reestablish the length and rotation of the leg. Concurrently, the vascular team can harvest a vein graft from the opposite leg if needed. If there is an open wound and exposed bone, initial débridement and irrigation should be performed to remove debris or necrotic tissue. Complete wound débridement may sometimes be delayed for ischemic limbs until revascularization has been accomplished. Definitive revascularization is then performed by the vascular team. Revascularization is more likely to benefit the patient when the level of injury is in the upper calf or popliteal region. Four-compartment fasciotomies are routinely performed after arterial repair due to “reperfusion” capillary leakage causing compartment syndrome after blood flow is restored to ischemic tissue. Fracture fixation must create adequate skeletal stability without adding to soft tissue injury. External fixation with the inclusion of the foot, or a locked IM nail, may be considered. An intraoperative arteriogram can be performed to confirm adequate blood flow after arterial repair and fracture stabilization. An early return to the operating room for wound assessment and care should be routine and should involve the vascular and orthopaedic surgery teams.
Patients with popliteal artery trauma have a high risk of amputation, in cases of both blunt (33%) and penetrating (25%) trauma. Risk factors for amputations in these patients include combined artery, vein, and nerve injury and delayed transfer to a treating institution with a vascular surgeon.
A detailed discussion on the management of vascular injuries is available in a previous chapter in this text.
Acute Compartment Syndrome of the Leg
Tibial shaft fractures are the most common injuries associated with compartment syndrome. Compartment syndrome may develop in any tibial fracture, no matter the severity or mechanism, whether open or closed. Vigilance is necessary during the first several days after every tibial fracture. Risk factors are open fractures, displaced proximal fractures, segmental or markedly displaced concomitant fibular fractures, and segmental fractures. Muscular men younger than 35 years of age are commonly affected. A recent study reported an incidence of 11.6% of acute compartment syndrome in adolescents (14 years of age or older) with tibial fractures.
Compartment syndrome is initially characterized by pain and swelling. Neurologic function, pulses, and skin perfusion are usually affected later in the course of compartment syndrome. Manual palpation of the compartments has poor diagnostic value in assessing for compartment syndrome. In a conscious patient, pain elicited by passive stretching of a muscle within the compartment can support the diagnosis of compartment syndrome (e.g., anterior compartment pain is produced by passively plantar flexing the patient's toes, and deep posterior compartment pain is assessed by passive toe dorsiflexion). Unfortunately, it is often difficult to assess if the pain is from compartment pressure or fracture. Pain by itself is a subjective measure that varies from person to person. It is, therefore, often the case that documentation of thorough repeated physical examinations and analgesic use during the first 24 to 48 hours may be the only way to detect an elevation in compartment pressures and the development of compartment syndrome. In the patient who is unconscious, obtunded, or insensate, physical examination is unreliable, necessitating the use of repeated or continuous direct intracompartment pressure measurements to detect trends in compartment pressure elevations and the development of compartment syndrome.
Patients who complain of increasing severe pain or neurovascular compromise should initially have the splint or cast loosened. The splinting materials, including the soft cast padding, must be loosened or completely cut to allow increased space for the leg. A circumferential cast should be bivalved and soft cast material cut completely to allow for increased space. If this fails to provide immediate relief and there is a continued increase in pain, swelling, or progressive motor and sensory deficits, the diagnosis of compartment syndrome should be assumed, and an emergent, thorough four-compartment fasciotomy should be performed.
Single compartment pressure measurements should not have a major role in the diagnosis of compartment syndrome, unless elevated. If the awake and alert patient has clinical signs of compartment syndrome, measurement of low compartment pressures may delay necessary treatment. If that patient does not have clinical signs of compartment syndrome, pressure measurements should not be ordered. Repeated or continuous measurements have little value in the alert and oriented patient where adequate serial clinical examinations can be performed. For the obtunded or unconscious patient, however, continuous compartment pressure measurement may be the most reliable way for early diagnosis of compartment syndrome.
In North America, most commonly, a solid-state transducer intracompartment (STIC) catheter system is used for measurement. The system needs to be adequately charged for accurate use. A disposable syringe preloaded with fluid is connected to a measuring instrument and a disposable needle-catheter. After the system is purged with fluid, the monitor is zeroed at the level of the compartment being tested. The needle is then inserted through the fascia and into the compartment. Measurements may differ according to the location of a puncture in the compartment. For this reason, it is our preference to measure in three separate locations in the compartment. We expect to find the highest pressures near the fracture site. The highest measured pressure is used for the decision-making process.
Another method is to use a 16-gauge intravenous catheter attached to an arterial pressure gauge line transducer arterial line catheter.
Compartment pressures above 30 mm Hg or within 30 mm Hg of the patient's diastolic pressure support the diagnosis of compartment syndrome. To avoid overdiagnosis of compartment syndrome, measurements should be performed either preoperatively or postoperatively because diastolic pressure can decrease during general anesthesia.
Care should be taken to unweight the posterior superficial and deep compartments during measurements. Increase external pressure may cause an inadvertent increase in compartmental pressure measurement.
Once the diagnosis of compartment syndrome is made, urgent four-compartmental fasciotomy is performed to lower interstitial fluid pressure, preserve capillary blood flow, and permit survival of nerve and muscle tissues that are sensitive to ischemia. Complete fasciotomies include the whole length of the compartment's musculature. During the procedure, preserve the neurovascular structures as much as possible, including veins, arteries, and nerves. Four-compartment fasciotomies can be performed in a dual-incision or single-incision manner. In the dual-incision method, the two incisions are at the mid-medial and mid-lateral aspects of the limb. In the single-incision method, the four leg compartments are released using a single lateral incision. Skin flaps are elevated to allow access to the anterior and posterior aspects of the fibula. Compartment syndrome may occur up to several days after fixation of the tibial shaft fracture. Regardless of the timing, the fasciotomy wounds are treated by fracture stabilization, negative-pressure wound dressings, and repetitive returns to the operating room for irrigation and débridement. Attempted delayed closure of the wound, suture tightening, and possible meshed split-thickness skin graft (STSG) are all methods for closure of the wounds.
A detailed discussion on the diagnosis of compartment syndrome, fasciotomy approaches, and methods for wound closure is available in Chapter 16 .
Key Point: Emergent Treatment
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Compartment pressures above 30 mm Hg or within 30 mm Hg of the patient's diastolic pressure support the diagnosis of compartment syndrome.
The Polytrauma Patient and Damage-Control Orthopaedics
Patients with multiple injuries are more likely to have severe tibial fractures. Life-saving, limb-saving, wound management, and fracture stabilization procedures are generally carried out in that order. Although a fracture table may be desired for IM fixation of the femur, it provides a poor surface for exposure of a tibial fracture, especially if extensive débridement or vascular repairs are necessary. One viable option in patients with ipsilateral femur and tibia fractures is to nail the femur in a retrograde fashion and then nail the tibia. Another approach may be splinting the tibia, nailing the femur, and then moving the patient to a radiolucent operating table for treatment of the tibial injury. If there is a vascular insufficiency, elevated compartment pressures, or open tibia fracture, treatment of the tibia fracture may be prioritized over the femur. Initial femur external fixation for temporization can also be considered. Patients with multiple lower extremity injuries are best placed on a radiolucent operating table, where all fractures can be treated definitively or in a staged manner. The sequence of treatment for open tibia fractures may be débriding of open fractures with sharp and blunt dissection of all contaminated and nonviable tissues with copious irrigation. This is followed by reestablishing a sterile field, then reducing and fixing diaphyseal fractures with an IM nail or external fixator, depending on physiologic stability, soft tissue assessment, and fracture pattern. The use of a radiolucent table in multiply injured patients in conducive to comprehensive management by multiple teams.
Damage-control orthopaedics currently appears to be the treatment of choice for patients with severe polytrauma who are at high risk of developing systemic complications, such as acute respiratory distress syndrome (ARDS) and multiple organ failure (MOF). In general, it is thought that patients with severe trauma who are under-resuscitated can suffer successive “inflammatory loads,” potentially overwhelming their immune response and leading to MOF. A detailed discussion on damage control orthopaedics is available in Chapter 11 .
Mangled Extremity
Severe limb- and life-threatening tibial fractures in the polytrauma patient deserve serious consideration of amputation. The expedient débridement of crushed tissue may be in the patient's overall best interests. Several scores have been developed to help the surgeon decide when to amputate a leg with severe soft tissue injury. However, the validity of these scores has been questioned.
In a prospective (level II evidence) study, the Lower Extremity Assessment Project (LEAP) study group showed equivalent outcomes between limb salvage and amputation in open lower extremity injuries with high risk for amputation after midterm follow-up. In a follow-up report by the same group, the projected lifetime health care cost for the patients who were treated with amputation was three times higher than that for those treated with reconstruction. The authors recommended that reconstruction is a reasonable goal at an experienced Level I trauma center. More recently, however, in a study performed by the US military, the Military Extremity Trauma Amputation/Limb Salvage (METALS) study group reported superior outcomes for major lower extremity trauma undergoing amputation compared with limb salvage. This was a retrospective (level III evidence) study on 324 military men faced with a decision to either amputate or salvage a severe lower extremity injury. After adjustment for covariates, participants with an amputation had better scores in all Short Musculoskeletal Functional Assessment (SMFA) domains compared with those whose limbs had been salvaged. They also had a lower likelihood of posttraumatic stress disorder (PTSD) and a higher likelihood of engaging in vigorous sports. There were no significant differences between the groups regarding the percentage of patients with depressive symptoms, pain interfering with daily activities (pain interference), or work and/or school status. However, the retrospective nature of the study and the low response rate (about 60%) raise concern for selection bias. Moreover, military recruits are placed in a multidisciplinary motivational program after amputation. Therefore these data may not be applicable to the nonmilitary population. A detailed discussion on the management of the mangled extremity is available in a previous chapter of this text.
Regardless of the definitive management decision, thorough irrigation with normal saline solution or lactated Ringer's solution and a thorough mechanical débridement should be performed initially. All devitalized muscle, skin, and bone without articular cartilage that is devoid of soft tissue attachments must be excised sharply in accordance with the surgeon's clinical decision. Conversely, viable muscle and fasciocutaneous tissue should be saved, protected, and kept from desiccation for possible use in the definitive soft tissue reconstruction. If a decision is made to amputate the limb, it is often wise to perform at least one additional irrigation and débridement procedure before closure of the wound. A length-preserving amputation that retains any irregular but grossly viable muscle and skin is performed, rather than creating formal flaps for closure at the initial débridement. Until the wound is ready to be closed, a negative-pressure dressing (NPD) can be useful. A vessel loop applied in the shoelace technique can be used to preserve skin length (see Fig. 64.3 ). Antibiotic beads can also be used before wound closure to reduce the risk of infection. A detailed discussion on the definitive management of traumatic amputations is available in Chapter 72 .
Closed Tibial Shaft Fractures
Indications for Definitive Care (Surgical Versus Nonoperative Care)
The majority of closed tibial fractures are treated operatively, specifically using reamed IMN. However, it is important to remember that some tibial fractures may also be successfully managed nonoperatively. The surgeon should, therefore, have a clear understanding of the indications for operative treatment as well as the details of nonoperative management.
Definitive indications for surgical treatment of tibial shaft fractures include tibial fractures associated with limb-threatening injuries and tibial fractures associated with a displaced intraarticular extension. Limb-threatening injuries include arterial injuries, compartment syndrome, crush injuries, and open tibia fractures. These patients need to go to the operating room for urgent treatment of the limb-threatening injury. Unless the patient becomes too unstable for surgery, it is difficult to justify continued nonoperative management of the tibia at this point.
Tibial fractures associated with ipsilateral femur fractures (the so-called “floating knee” injury) are also considered a definite indication for surgery. Patients with contralateral lower extremity injuries and most patients with multiple injuries, particularly if tibial fracture fixation will significantly aid their management or provide earlier ambulation, benefit from surgical intervention.
In closed or type I open tibia fractures, good results have been reported with nonoperative management. In a classic paper, Sarmiento and colleagues reported excellent results in 1000 consecutive tibia fractures treated with initial casting and then transitioned into a functional brace. These patients had meticulous nonoperative management with close monitoring and expert cast and brace treatment. Included in this study were transverse tibia fractures that could be closed reduced with less than 15 mm of shortening. The average time in a cast, before transitioning to a brace, was 3.7 weeks (range, 1.4 to 23 weeks). The average healing time was 18.1 weeks (range, 6.7 to 75 weeks). The nonunion rate was 1.1%, with an average of less than 5 mm of shortening (only 10% had more than 1 cm of shortening) and less than 6 degrees of angulation (only 5% had more than 8 degrees of varus).
Some tibial shaft fracture patterns, however, may have unacceptable results with nonoperative treatment. In one prospective study on 50 conservatively treated tibial fractures, the rate of malunion was 75% in proximal and distal shaft fractures and 25% in midshaft fractures. Spiral fractures with displacement of more than 30% of the shaft width had a 46% failure rate with conservative management. Oblique and severely comminuted fractures have been associated with significant shortening. In a classic study by Nicoll, four factors were associated with delayed union: displacement, comminution, severe soft tissue injury, and infection. Severe soft tissue injury coupled with prolonged immobilization was also associated with an unacceptable degree of stiffness.
Few studies directly compare operative versus nonoperative management of tibial shaft fractures. Most comparative studies tend to show benefit to surgical management over casting. In a prospective randomized study comparing conservative treatment to plate fixation of 100 tibial fractures, healing time and malunion were significantly lower with operative treatment, whereas infection rate for open fractures was lower in the conservative treatment group. In a retrospective review, IMN was compared with casting for closed, open type I, and open type II tibial shaft fractures. IMN showed superior results to casting in nonunion rate (1.7% vs. 9.9%), malunions (0% vs. 4.3%), return to work (22 vs. 25.8 weeks), and treatment failure (0% vs. 13.4%). Casting had a lower rate of infection (1.4% vs. 3.3%). In another prospective randomized study comparing conservative treatment to IMN in 62 (33 castings and 29 nailings) tibial fractures, surgical treatment was found to be clearly superior. Time to union (15.7 vs. 18.31 weeks) and time off work (13.5 vs. 23 weeks) were significantly shorter in the nail group. Nailing patients required fewer postoperative radiographs and clinic visits. Malunion was 18% in the conservative group versus 3.5% in the nail group. Range of motion (ROM) was significantly lower in the conservative group initially but was similar in final follow-up. This study was stopped early because conservative management was deemed unethical by the authors in light of the significantly better results in the nail group. In a retrospective study with 47 nailings and 52 castings of tibial shaft fractures, nailing was superior to casting in time to union (18 vs. 26 weeks), nonunion rate (1% vs. 5%), and all functional outcome scores (knee, ankle, and Short Form-36 [SF-36]) at 4.4 years of follow-up. In a prospective randomized study of 53 patients with unilaterally displaced tibia fractures (closed or type I open), patients treated with an IM nail were found to have a shorter time to union (19 vs. 25 weeks), lower rate of delayed union (6% vs. 16%), and better functional outcomes at 3 months after injury. Fourteen out of the 26 patients treated with a cast experienced redisplacement in the cast that required intervention at the 1-week follow-up. Finally, in a literature-based cost analysis, compared with casting, reamed IMN was shown to have lower costs to the government (US$3400 for reamed IMN vs. US$5000 for casting) and society (US$12,500 for reamed IMN vs. US$17,300 for casting).
In summary, there seems to be an advantage for surgical management of tibial shaft fractures in all but the low-energy fractures that can be adequately closed reduced (<5 degrees of varus/valgus, <10 degrees of sagittal angulation, <5 degrees of rotation, <1 cm of shortening) and that reduction can be maintained in a cast and later with weight bearing in a functional brace. Patients should be informed of their choices. If nonoperative management is chosen, the surgeon must be familiar with casting and bracing techniques (described in the next section), and the patient must be committed to frequent clinic follow-up with the necessary adjustments in treatment.
Key Points: Treatment of Closed Tibial Fractures
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Definitive indications for surgical treatment of tibial shaft fractures include tibial fractures associated with limb-threatening injuries and tibial fractures associated with a displaced intraarticular extension.
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Tibial fractures associated with ipsilateral femur fractures (the so-called “floating knee” injury) are also considered a definite indication for surgery.
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IMN is the surgical treatment of choice for most tibial shaft fractures. The insertion may be performed via a supra- or infrapatellar approach. In patients who have a spiral or short oblique tibial fracture, the reduction can be facilitated and maintained with the pointed reduction clamps inserted through small stab incisions about the fracture site.
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A temporary external fixator frame may be used to correct and control the coronal angulation more easily. Procurvatum and recurvatum can be controlled with a bump under the leg or by adding an anterior pin that is connected to the frame.
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The selected entry site for initial guidewire must lie over the long axis of the tibial canal and on the anterior edge of the tibial plateau. Generally, no more than 1 to 2 mm of reaming is carried out after the first reamer makes contact with the cortex internally. A nail of a diameter 1 to 2 mm less than the last reamer is then inserted over the guidewire.
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Plates can be used for rigid fixation and absolute stability when fracture comminution is minimal. Percutaneous plate fixation techniques can be used for relative stability to induce callus formation and potentially more rapid healing in patients with multifragmentary fractures.
Nonoperative Treatment
Tibial Cast Application
Advance preparation is a great aid to reduction and cast application. Before beginning, it is necessary to have close at hand ample cast padding, usually as 4- to 6-inch rolls; plaster or fiberglass rolls, 4 to 6 inches wide; a bucket of water; and a cast saw. The patient's radiographs should be visible. A seat is helpful for the person applying the cast. The task requires at least two people: one to hold the leg and the other to apply the cast. The patient must be as comfortable as possible, and his or her cooperation and understanding should be encouraged. An intravenous line should be in place. Analgesia should be provided before and during the cast application as needed.
The patient is positioned recumbent on an examining or operating table. Both legs are evaluated so that rotational alignment and contours of the normal limb can guide reduction and cast molding. This can be facilitated by hanging both legs over the end of the examination table. Alternatively, the injured leg can be abducted at the hip and hung over the table's side. There must be enough room to allow padding and plaster to be rolled around the upper calf. The cast is applied in two parts. Almost always (except for very proximal fractures) the lower part is applied first. The assistant holds the forefoot, steadying the leg and maintaining its alignment, especially regarding rotation and plantigrade foot position. With knee flexion, the tibia can rotate significantly on the femur. It is, therefore, important to assess rotational alignment using the relationship of the second toe to the tibial tubercle, as demonstrated by the opposite limb. The assistant's fingers are placed under the plantar surface, with the thumb over the dorsum of the foot. Thus plantar flexion and inversion (supination) are controlled, both of which tend to occur and subsequently interfere with weight bearing in this cast. Although ankle equinus is occasionally the alternative to apex-posterior angulation of a distal tibial fracture site, it is usually avoidable if, as Sarmiento and Latta suggest, the initial cast is applied with the foot in neutral.
The assistant maintains foot position as chosen while ample cast padding is rolled onto the foot (including the thumb and fingers of the assistant) and up as high on the leg as the flexed knee will allow ( Fig. 64.7A ). Developing soft tissue edema and the leg's characteristic bony prominences argue for thick padding, as does the likelihood that the cast will need to be cut in the near future while the leg is still swollen. Because the patient will be supine, extra padding is required posterior to the heel, where much of the limb's weight will be borne during recumbency. The malleoli, the fibular head and neck with the surrounding peroneal nerve, and the subcutaneous tibial border also require extra padding. The padding is palpated to ensure its adequacy, supplemented if necessary, and then a thin cast (8 to 10 layers of plaster or 5 to 8 layers of fiberglass) is rolled on from the metatarsophalangeal joints to 1 or 2 inches below the top of the padding at the knee. The plantar surface may be extended to support the toes, but the dorsum should be placed or trimmed proximal to all five metatarsophalangeal joints.
Some surgeons believe that plaster is easier to apply and mold than fiberglass. However, it should be left thin to simplify alterations and avoid unnecessary weight. As the plaster sets, molding is carried out to make the shape of the medial border of the cast concave, similar to the patient's opposite leg; a straight cast produces valgus malalignment. The surgeon should ensure that the foot position has been maintained.
Once the lower leg portion of the cast is firm, it can be lifted and held horizontally, with the knee flexed 10 to 15 degrees and the thigh sufficiently clear of the table surface to allow padding to be extended proximally an inch beyond the intended top of the cast, approximately two-thirds of the way up the thigh (see Fig. 64.7B ). Cast material is then rolled on, overlapping by 4 to 6 inches the top of the previously applied lower portion. It is essential that there be adequate padding at the junction of the two segments, but no padding should lie between the layers of the cast material.
As soon as is practical, AP and lateral radiographs are obtained of the entire tibia within the cast, and a decision is made as to the provisional adequacy of reduction and cast application. Only if there is marked deformity or risk of skin compromise should the appearance of these radiographs lead to changing the cast. Adjustments such as wedging, applying a new cast, or changing to another mode of treatment are better deferred until swelling has resolved.
The long leg cast just applied may need to be loosened to accommodate potential or actual swelling of the injured limb. Although it is always wise to anticipate such swelling, many low-energy tibial fractures can remain in an intact, well-padded cast in patients who are reliable and understand the potential issues with cast management. Routine splitting of all initial tibial casts results in unnecessary manipulation and may compromise the cast's stability.
A cast may be loosened in several ways. If swelling is severe and likely to progress, the cast should be converted to a posterior trough splint. This is done by removing the anterior portion of the cast and bending both sides outward, wide enough to permit removal of the leg and to avoid any pressure on the sides of the limb. The padding is completely cut anteriorly and folded outward as well, so the padding is not a source of constriction, and to allow examination of the limb. Removal of part of the medial cast wall at the ankle can allow assessment of the posterior tibial pulse, if this is needed (see Fig. 64.6 ). A practical concern about removing strips and windows from casts is that the stability of the cast may be compromised, and swelling may occur preferentially at those sites. The result may be a plaster cast that fails to immobilize the injured limb. Such an outcome does not prevent pain and may cause additional tissue trauma. The adequacy of immobilization must be frequently reassessed.
Removal of an anterior strip of plaster can interfere with the usefulness of the cast. Somewhat better stability with decompression may be provided by “bivalving” a cast, with medial and lateral longitudinal cuts placed just a bit anteriorly to the mid-lateral lines of the cast to maximize stiffness and durability of the posterior portion, but not so far anteriorly that the opening is too narrow for removal of the leg. A bivalved cast can be loosened as needed and held securely together with several encircling loops of adhesive tape. In addition to longitudinal cuts in the cast, windows may be removed to check questionable areas of skin, to relieve pressure over a bony prominence, or to assess pulses. The removed cast window should be retained and taped securely in place when the opening is not in use. Doing this adds to the strength of the cast and maintains enough overlying pressure to avoid “window edema,” or swelling of the soft tissues into the window defect.
If a cast is left intact around a fresh tibial fracture, there must be fail-safe arrangements for it to be released if the patient develops significant swelling, pain, or neurovascular compromise. Although tibial fracture patients typically require hospitalization, one may occasionally be sent home with a low-energy injury if he or she is able to use crutches and perform transfers and has adequate assistance and prompt transportation back to the hospital. Whether as an outpatient or in the hospital, the patient should keep the injured leg elevated and should be observed closely for increasing pain, decreasing sensation, and loss of palpable toe muscle strength. Pain after a tibial fracture is largely relieved by adequate splinting. Standard doses of parenteral or oral analgesics should be effective and be required gradually less frequently over time. After 1 or 2 days, oral analgesics should be sufficient. Increasing needs for analgesia after splinting suggests increasing swelling, possibly increasing compartmental pressures, and neurovascular problems. The cast should be reevaluated frequently to treat these problems.
Functional Cast or Brace
Sarmiento reports impressive results in selected patients with less displaced, usually lower-energy tibial shaft fractures. His technique advises that functional closed treatment be limited to closed injuries that have no more than 15 mm of initial shortening or are axially stable, reduced transverse fractures. Functional treatment of tibial fractures has been satisfactory for properly selected patients, yielding low rates of nonunion, infection, and significant malunion.
Functional bracing begins with a closed gravity realignment and application of an initial cast, as described previously. In addition to injury severity, the adequacy of reduction in this cast and the patient's subsequent clinical course are the most important determinants of whether closed functional treatment is appropriate. The amount of soft tissue damage determines the shortening that may occur. Ultimate shortening is usually predictable from the amount of shortening apparent on the initial radiographs. Brace treatment is rarely appropriate if there is more than 15 mm of shortening, as measured by fragment overlap. Poor control of angulation in a long leg cast is also a contraindication to functional bracing, unless it is corrected by reapplication of cast or brace. Angulation should not exceed 5 degrees in the AP radiograph and 10 degrees in the lateral radiograph.
The following protocol for closed functional treatment of tibial shaft fractures is similar to that which Sarmiento and his coworkers developed. The first stage involves the application of a gravity reduction cast, as previously described. An acceptable reduction must be confirmed. Initially, the patient rests his or her leg with elevation slightly above heart level. Ice packs applied to the cast may increase comfort. Analgesics are usually required. Progressively increasing ambulation is encouraged, with weight bearing as tolerated using a removable cast boot and crutches or a walker as needed. The patient is asked to elevate the limb when not walking and to do isometric exercises with the immobilized muscles and active and passive exercises for the toes. He or she should be reassured about the inevitable motion of fracture fragments felt inside the cast and the benefits of progressive weight bearing on the fractured limb. In addition to the exercise program, physical therapy may help with gait training on level surfaces, on stairs, and for transfers. Once patients are comfortable and mobile enough to manage at home and any necessary assistance has been arranged, they are discharged to outpatient follow-up. They are instructed to report promptly any cast problems, increasing pain, motor or sensory deficit, or excessive swelling that is not rapidly relieved by rest, elevation, and milder analgesics. An office or clinic visit 1 or 2 weeks after discharge permits reassessment of comfort, gait, swelling, neuromotor function, cast integrity, and clinical as well as radiographic alignment.
A patellar tendon-bearing (PTB) walking cast or a prefabricated functional PTB brace from knee to foot with a hinged ankle is applied when the patient can comfortably bear partial weight in the long leg cast and early fracture consolidation has occurred ( Fig. 64.8 ). This usually occurs between 3 and 5 weeks after injury. Proximal tibial fractures may be better controlled in a long leg cast, but deformity is common due to the pull of the extensor mechanism. If knee motion is desired for such patients, hinges and a thigh cuff can be added to its below-knee portion. An effective method for doing this is to use a prefabricated hinged brace or a fiberglass below-knee cast, molded as shown in Fig. 65.8A , to which are attached the hinges and adjustable thigh cuff of a commercially available modular fracture brace. This may have either a fixed or a hinged ankle, depending on the degree of immobilization desired. Custom braces can be helpful for patients who are hard to fit with prefabricated ones. Zagorski et al. showed equivalent stabilizing efficiency of plaster casts and custom and prefabricated fracture braces and no additional benefit from the classic PTB proximal extensions for experimental midshaft tibial fractures.
Radiographs through the cast or brace are initially checked every 2 to 3 weeks to ensure maintenance of satisfactory alignment. Minor degrees of angulation can be corrected with cast changes or wedging. However, the latter may render the cast less suitable for weight bearing, so once the fracture is “sticky” enough to permit only bending rather than translation of fragments, it is better to change the cast or move on to a brace rather than adjust the alignment with wedging. Significant difficulty obtaining or maintaining satisfactory fracture alignment with cast or brace suggests the advisability of surgical reduction and fixation.
Radiographs are obtained in the brace initially and again in 1 or 2 weeks, at which time it is also essential to reconfirm that the brace fits well, without skin or nerve irritation, and that the patient is maintaining and adjusting it properly. Thereafter (usually from 6 to 8 or more weeks after a low-energy tibial shaft fracture), it is usually possible to monitor the patient with visits and radiographs every 4 to 6 weeks. The brace is continued until the patient is fully weight bearing without discomfort; tenderness and warmth are absent at the stable fracture site; and radiographs in the AP, lateral, and both oblique projections confirm union with mature bridging callus.
At this point, if significant residual muscle weakness and atrophy persist, the patient's endurance is not yet normal, and the skeleton is weaker than normal as a result of disuse atrophy. Therefore a continuing rehabilitation program with avoidance of risk and contact sports is advised, while encouraging repetitive progressive loading. These graded, progressively increasing exercises should continue until the patient's activity level and tolerance reach an appropriate goal. This often requires 6 to 12 months from the time of injury.
Skin problems associated with braces are usually rare but should be watched for. If they develop, padding or other brace adjustments may be required. All patients need at least two socks, one to wash and the other to wear.
If the alignment of a tibial fracture becomes unacceptable during closed treatment, correction may be possible by manipulation and revision of the cast or brace. This may require a return to a long leg cast, perhaps with temporary restriction of weight bearing. If adequate correction cannot be obtained and maintained, then an alternative treatment should be selected and carried out before the fracture heals in unsatisfactory alignment. Depending on the deformity, its mobility, and the fracture configuration, this may require a carefully planned open reduction. If so, bone grafting should be considered. Closed reduction and fixation with an IM nail is a better option, if possible. Rarely, an external fixator may be used to realign a healing fracture.
Surgical Treatment
In North America and Europe, the surgical treatment of closed tibial shaft fractures is performed almost exclusively with IMN. Plating and external fixation can be used in austere environments or when there are contraindications to IMN, such as canal diameter of less than 6 mm, deformity of the canal, severe contamination of the canal, previous total knee surgery, or previous knee arthrodesis ( Box 64.1 ). External fixation may also be used in the unstable polytrauma patient as part of a damage control strategy. There are no definitive studies that delineate the preferred timing for surgical fixation of the isolated closed tibia fractures. Despite the association of tibia fractures with increased soft tissue compromise, it is not clear whether early fixation has an effect on the risk of compartment syndrome. Restoration of compartment length decreases muscular compartment volume when the fascial compartment is intact. Theoretically, this could increase the risk of compartment syndrome with closed IMN. The actual incidence of this complication is not well defined. Moehring and Voigtlander performed intraoperative pressure measurements during 26 tibial shaft fracture nailings. They found persistently elevated pressures (>40 mm Hg) that necessitated immediate four-compartment fasciotomy in 35% of patients. However, McQueen and colleagues, with continuous pressure monitoring during and after IMN of acute tibial fractures, found only a 1.5% incidence of compartment syndrome and no effect of delaying treatment by more than 24 hours. Tornetta and French found only transient elevation of pressure during nail passage and no compartment syndromes in 58 patients nailed without traction and without reaming. Once the leg is splinted, elevated, and iced, it seems safe for the patient to wait for the surgery to be performed when the proper surgical team and equipment have been assembled. The patient can also be transferred to a different facility for definitive fixation without apparent adverse effects. In our practice, we usually surgically treat closed tibial shaft fractures within 48 hours of their arrival. Our fixation method of choice is reamed IMN with proximal and distal interlocking screws.
Box 64.1
Indications for Tibial External Fixation
- 1.
Intraoperative reduction aid for fixator-assisted nailing or minimally invasive plating (substitute for bone distractor)
- 2.
Rapid stabilization for associated vascular injury
- 3.
Temporary support of severely injured soft tissue
- 4.
Open fractures with exceptional medullary contamination
- 5.
To permit a second look, through the fracture site, at a posterior soft tissue injury
- 6.
Disaster or battlefield setting
- 7.
Third World, without institutional capabilities for intramedullary nail or plate fixation
- 8.
Definitive fixation for fractures not anatomically suited for intramedullary nailing (e.g., proximal or distal fracture, canal deformity, or previous osteomyelitis)
- 9.
Reconstruction of severe injuries (e.g., compression–distraction or segmental transport)
- 10.
Optionally as definitive fracture fixation
- 11.
Treatment of fracture site infection, typically after previous internal or external fixation
Surgical Anatomy
The tibia has three distinct zones related to tibial nailing: the proximal metaphysis, middle diaphysis, and distal metaphysis. In the diaphysis, the medullary canal becomes tubular, with thick walls, especially anteriorly, where the prominent crest of the tibia occupies nearly a third of the diameter of the entire bone. Although the IM canal is tubular, the shaft of the tibia is in the shape of a right triangle in cross section with the lateral and posterior cortices as the sides and the medial cortex (shin) as the hypotenuse of this triangle. The canal is positioned at the posterolateral corner of this triangle. This nuance is important to understand when inserting IM nails. One implication of this type of triangular tibial shaft shape is that the tibial crest, palpated at the anterior leg, is a lateral structure with the IM canal lying slightly medial to it. The dense cortical bone of the shaft is dense, and drilling generates significant heat during penetration. It is essential when placing screws or pins across the tibial diaphysis to remember the thickness of the anterior crest and to aim posteriorly enough to bisect the internal rather than the external diameter and thus obtain a true bicortical purchase (see Fig. 64.2 ).
Intramedullary Nailing of Closed Tibia Shaft Fractures
IMN is the surgical treatment of choice for most tibial shaft fractures. Nailing is typically performed with fluoroscopic guidance. However, IMN may also be performed with minimal imaging in austere or resource-deprived environments. Nails provide relative stability and should be thought of as “internal splints.” However, in fractures of the proximal or distal tibia or with comminution, the locking screws bear all of the weight. Healing occurs by callous formation providing there is adequate soft tissue coverage and blood supply.
Positioning.
The patient is positioned supine on a radiolucent operating table ( Fig. 64.9 ) or on a fracture table set up for IMN of the tibia. On such a table, the leg can be free, supported with a radiolucent triangle, or supported with an external fixator or large distractor. If a fracture table is used, the proximal leg support must be well padded. It is positioned posterior to the distal femoral shaft and not posterior to the popliteal fossa. If compression of the popliteal fossa occurs during the surgery, there may be excessive pressure on neurovascular structures. With a fracture table, rotational alignment must be assessed before draping and intraoperatively. Fluoroscopic visualization and provisional reduction should also be performed before draping. A tourniquet may aid exposure but should not be used during reaming because the absence of blood flow may increase the risk of thermal necrosis. In our practice, we do not use a tourniquet routinely.
Typically, the knee must be flexed more than 90 degrees to permit free access to the tibia nail entry site if using an incision distal to the patella. However, it is also possible to insert the nail with the knee in a semi-extended position with the patella retracted or incision proximal to the patella. Positioning must allow adequate fluoroscopic visualization in the AP and lateral planes from the tibial plateau to the ankle (see Fig. 64.9 ).
The surgeon can stand on the medial or lateral side of the injured leg, with the fluoroscope on the opposite side. Standing on the medial side simplifies medial-to-lateral insertion of locking screws.
Surgical Approach
Nail Insertion With the Knee Flexed.
Choosing the infrapatellar approach with the knee flexed, the incision is centered over the long axis of the tibia, which is commonly anterior to the lateral intercondylar eminence. This longitudinal incision can be located medial, lateral, or centered over the patellar tendon. The incision can extend from the tibial tubercle to the mid-portion of the patella; however, in most instances, only the most proximal 2 to 3 cm of this incision is necessary. Dissection is carried out carefully to the patellar tendon. If the approach splits the patellar tendon, the peritenon is sharply dissected and the patellar tendon sharply incised along its fibers. If the approach is medial or lateral to the patellar tendon, the peritenon is kept intact if possible. Next, an awl or a guidewire and sleeve are inserted into the anterior tibial plateau at the area of the sweet spot. The knee joint is avoided.
Insertion With the Knee Extended.
Insertion in the semi-extended position begins with an incision proximal to the patella that extends through the quadriceps mechanism. A cannula is then placed between the patella and the femoral trochlea to protect the articular cartilage. A guidewire is then placed through the cannula and into the proximal aspect of the tibia at the sweet spot. During this approach, care must be taken to avoid damaging the articular surface of the patella or trochlear groove.
Reduction Techniques.
The reduction is most often obtained before IM guidewire and nail insertion. It is usually possible to manually reduce the fracture in the acute situation. One surgeon (usually the more experienced surgeon on the team) applies manual traction while simultaneously correcting coronal plane angulation and rotation. Sagittal plane angulation can be corrected using a soft bump behind the leg. A second surgeon is then able to insert the IM guidewire, ream the canal, and insert the nail ( Fig. 64.10 ).
In patients who have a spiral or short oblique tibial fracture, the reduction can be facilitated and maintained with the pointed reduction clamps inserted through small stab incisions about the fracture site. After rotation is corrected manually, one clamp is used to correct and hold reduction of the coronal plane while the other is used to correct and hold the reduction of the sagittal plane ( Fig. 64.11 ). Attention should be given to the correct location of the stab wounds to allow positioning of the reduction clamp tines without excessive pressure on the skin (see Fig. 64.11 ). Typically, the medial and anterior tines are inserted through stab incisions directly over the subcutaneous surface of the medial and anterior cortex of the tibia. The lateral and posterior tines are inserted through stab incisions that are 3 to 4 cm lateral to the tibia crest. The tine is inserted first subcutaneously and then advanced medially over the anterior muscle compartment. Once reaching the lateral cortex of the tibia, the tine is carefully advanced along the lateral cortex until reaching the posterior or lateral cortex. Care must be taken for the reduction clamp tip to stay touching the bone while it is being positioned. This will avoid neurovascular damage.
In fractures where it is difficult to correct shortening with manual traction (e.g., after significant delay from injury to surgery) or when there is significant comminution that prevents accurate length and alignment control, a distractor or temporary external fixator can be used to correct shortening, rotation, and angulation deformities. Moreover, the external fixator and distractor can maintain reduction during the nailing procedure. There are several pin placement patterns that can be utilized to achieve and maintain reduction of the tibia. When applying the femoral distractor, two 5.0-mm half-threaded pins are inserted unicortically from medial to lateral. The first pin is inserted parallel to the knee joint in the proximal tibia at the level of the fibular head and just posterior to the midline but anterior to the fibular head ( Fig. 64.12A ). The second pin is inserted parallel to the ankle joint in the distal tibia at the level of the ankle syndesmosis and over the posterior third of the ankle joint and anterior to the distal fibula (see Fig. 64.12B ).
We have found that it may be more challenging to control coronal plane angulation with a unilateral distractor (see Fig. 64.12 ). A temporary external fixator frame may be used to correct and control the coronal angulation more easily. A centrally threaded transtibial pin is inserted from lateral to medial parallel to the knee joint in the proximal tibia just posterior to the midline and anterior to the fibular head. A second, centrally threaded transcalcaneal pin is inserted from medial to lateral at the safe zone of the calcaneus. The two pins are then connected by two parallel bars to create a rectangular frame. The tibia is then manually reduced to the correct rotation, angulation, and length, and the frame is secured ( Fig. 64.13 ). Distraction jigs can then be used on either one of the bars to add length or to change angulation as needed. Procurvatum and recurvatum can be controlled with a bump under the leg or by adding an anterior pin that is connected to the frame. Care must be taken to position the frame on the posterior aspect of the pins to avoid collision of the frame with the tibial nail targeter.
Delay in treatment with callus formation or soft tissue entrapment in the fracture site may lead to the inability of the surgeon to close reduce the tibial fracture and allow insertion of the IM guidewire from the proximal to the distal fragments of the fracture (see the Nail Insertion and Fixation Technique section). The surgeon may opt to perform an open reduction if an adequate closed reduction cannot be achieved. If the open reduction is performed by disturbing the local soft tissues as little as possible, this technique may not compromise the result.
Nail Insertion and Fixation Technique.
The selected entry site for initial guidewire must lie over the long axis of the tibial canal, and on the anterior edge of the tibial plateau. Radiographically, this usually corresponds to a point just medial to the lateral tibial spine on the AP fluoroscopic image and immediately adjacent and anterior to the articular surface on the lateral fluoroscopic image.
After the guidewire is inserted through the correct entry site, it is advanced for 10 to 15 cm, and a rigid entry reamer is inserted over it to create an entry portal for the subsequent flexible canal reamers and nail. When using an infrapatellar approach, the knee is held in maximal flexion to allow passage of the reamers and nail parallel to the anterior cortex of the tibia. The skin overlying the distal pole of the patella must be protected to avoid trauma during the nailing procedure. The distal aspect of the patella and proximal skin can be protected by use of a cannula for the reamers, a shorter design of the proximal jig and jig bolt, and/or proximal extension of the incision over the inferior pole of the patella.
An IM guide is inserted through the entry portal. The tip of the guidewire is slightly bent to aid in navigating the wire across the fracture site. The wire is advanced by gentle tapping with a mallet on a wire grasper under fluoroscopic imaging. Once the wire reaches the distal fragment, it is advanced to the level of the physeal scar (approximately 1 cm above the tibial plafond) and “docked” in the distal tibia in the AP and lateral images. In the AP fluoroscopic view, the guidewire is positioned over the middle of the dome of the talus because the middle of the distal tibia flares medially. On the lateral view, the guidewire is placed at the junction of the anterior and middle thirds of the distal tibia because the tibia flares posteriorly.
Either a reamed or unreamed nail is then inserted over the IM guidewire. If a reamed nail is chosen, then flexible reamers are inserted one after another in increasing diameters. Typically, a diameter of 8.5 mm with an end-cutting flute is initially inserted, followed by 0.5- to 1-mm larger diameter reamers. Reaming is continued until bone chatter is heard and felt. Generally, no more than 1 to 2 mm of reaming is carried out after the first reamer makes contact with the cortex internally. A nail of a diameter 1 to 2 mm less than the last reamer is then inserted over the guidewire. For young patients with normal bone, we prefer to ream 1 to 1.5 mm larger than the nail diameter to avoid nail entrapment and still create a tight fit between the nail and the bone. A tourniquet is rarely needed to prepare the entry site. If it is used, the tourniquet must be deflated before reaming to aid heat dissipation. The most common cause of tibial necrosis appears to be forceful reaming of the medullary canal in a young patient with a small diameter canal and a thick cortex.
Once reaming is completed, the nail is inserted over the IM ball-tipped guidewire. Some authors recommend exchanging the distally bent guidewire with a straight non–ball-tipped wire to aid in removal of the guidewire after the nail is inserted. We have not found this to be a problem provided the distal tip ball-tip guidewire is bent properly. We recommend making one bend of 10 to 20 degrees approximately 2 cm proximal to the ball tip. This can be optimally performed using a wire grasper (T-handle) and pliers or one of the drilling sleeves from the set ( Fig. 64.14 ).
Once the nail has been fully inserted, fluoroscopy is used to verify that the proximal end of the nail is not too prominent relative to the entry site, and that fracture length, rotation, and alignment are adequate. A particular problem that may arise during insertion of the nail is fracture distraction or creation of a gap at the fracture site. To correct distraction in unstable fracture patterns or achieve compression in stable (transverse/short oblique) fracture patterns, the nail is “backslapped” after distal locking is performed. Adequacy of reduction and nail position is again evaluated. If the tibia is reduced, proximal interlocking is performed. If the fibula is not comminuted or has an easy cortical read, it can be used to assess length as well.
Current tibial IM nails have holes in various configurations for interlocking screws at both proximal and distal ends. The interlocking screws help control rotation and length in unstable fracture patterns. Because of the lower density of metaphyseal bone, we prefer to lock the IM nail with two proximal and two distal screws ( Fig. 64.15 ). The two proximal screws are typically inserted through the nail-targeting jig. The distal screws are typically inserted using a freehand technique with a fluoroscopic “perfect circle” method. When inserting the distal locking screws freehand, the image intensifier is aligned with a nail hole to create a perfect circle, indicating coaxial alignment of the C-arm and the screw hole in the nail. An incision is made through the skin and fascia, down to the cortex at this site. The tip of the drill is positioned on the lateral cortex of the shaft, aligned with the center of the circular image (creating a “packman” image). A hole is then drilled parallel to the radiograph beam of the C-arm. Imaging is used to verify the passage of the drill through the interlocking hole. A useful technique is to drill the near cortex and then gently tap the drill bit through the nail to the far cortex. We then verify that the drill bit is in the correct position within the nail aperture with the C-arm. Then we drill the far cortex. Screw length is then measured using a depth gauge, and a screw is inserted freehand using the same trajectory as the drill bit. The process is then repeated for the other distal hole. Different devices and imaging techniques have been developed in recent years in order to reduce the amount of time and radiation associated with the freehand technique. It is our preference to insert both proximal and distal interlocking screws from medial to lateral. Although lateral-to-medial screws distally may be theoretically less likely to injure the posterior tibial neurovascular bundle and superficial peroneal nerve, they are not as mechanically stable. AP and oblique distal locking screws require special attention to soft tissue anatomy.
Most statically locked tibial fractures heal with the locking screws in place. Most nail designs have one of the proximal interlocking holes designed for dynamic locking. The dynamization hole is oblong allowing controlled vertical compression of the fracture site with weight bearing.
Use of both proximal and distal locking screws, in a static-locked pattern, requires that the nail and screws endure forces not borne by the tibia. Thus the several components of a statically locked nail are at risk of fatigue failure, which occurs most commonly at the distal interlocking screw holes of the nail or when the screws break. Clinically, distal tibial fractures close to the nail's distal locking screws are most at risk of causing nail failure. Implant material and design, especially outer diameter, determine the strength and endurance of IM nails and locking screws.
Reamed Versus Unreamed Nailing.
Both reamed and unreamed nail designs are available for tibial nailing. Unreamed nails are of smaller diameter and can be solid. Reamed nails are cannulated, of larger diameter, and with larger interlocking screws. Although reamed nails offer an ultimately stronger biomechanical construct, unreamed nails have been suggested as a quicker, less traumatic option. However, the Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures (SPRINT) investigators found that there was a statistically significant decrease in reoperation rates in reamed versus unreamed nails.
IMN, with or without reaming, affects endosteal blood circulation. There is an immediate loss of medullary arterial flow with a variable thickness of bone necrosis around the nail. To compensate, the periosteal blood supply assumes a larger role in perfusing the cortex. If immobilization is sufficient and there is sufficient space between the nail and the internal surface of the cortex, then the medullary arterial system regenerates within a few weeks. Cortical necrosis is significantly less when a smaller diameter IM nail is inserted without reaming than when a larger diameter nail is inserted after reaming the medullary canal. This is the theoretical justification for using nonreamed nails for open tibial fractures. Clinical experience and research have shown the same amount of callus formation after both reamed and unreamed nails. On the contrary, shorter healing times and reduced reoperation rates have been demonstrated with reamed nails.
Unreamed tibial nails have smaller diameters and require smaller diameter locking screws, and they thus have an increased risk of mechanical failure, which might lead to loss of fracture fixation and alignment. Compared with larger diameter nails intended for insertion with reaming, their smaller diameter shafts, proportionately larger locking screw holes, and smaller locking screw diameters typically result in reduced ultimate strength and shorter fatigue life. Therefore, unless there is cortical contact between the proximal and distal fragments with a simple fracture pattern, limited weight bearing is advisable until healing of the tibia is advanced enough to protect the IM fixation. In practice, fatigue fracture of nonreamed IM tibial nails rarely occurs. Locking screw failure is not unusual, but it rarely leads to significant problems. However, the surgeon must discuss such possibilities with the patient when planning treatment. The surgeon must also keep in mind the problems of removal of broken locking screws, particularly of retrieval and removal of a broken solid IM nail. More difficult for the surgeon than mechanical failure of nonreamed tibial nails is the challenge of inserting them into a medullary canal that may be a poor fit because of its inner diameter, mismatched curvature, or both. A study from Sweden found that even 8-mm nails could not be inserted without reaming in a significant percentage of adults.
Reaming has been suggested as a possible cause for compartment syndrome or systemic effects after tibial fractures. Nassif and colleagues’ prospective randomized study showed no difference in compartment pressures between reamed and nonreamed nailing. Systemic effects of IMN, perhaps more of a concern regarding femoral fractures, have also been discussed as a reason for using nonreamed IM tibial nails. Although it is clear that medullary fat and debris enter the vascular system during IMN, there is little evidence that there are any significant clinical consequences. Systemic hemodynamic effects—increased central venous and pulmonary artery pressures and relative hypoxia—are related more to the tibial fracture than to IM nail insertion.
From the information currently available, it appears that medullary reaming is a beneficial part of IMN for most if not all closed tibial fractures.
Intramedullary Nailing After External Fixation.
External fixation offers a quick and less invasive means of stabilizing tibial shaft fractures that may benefit the patient with multiple injuries, with severe soft tissue wounds, or who will be transferred elsewhere for definitive care. The use of any IM nail after an external fixator may cause an increased risk of infection secondary to bacterial contamination through the pin sites. If infection of the fracture wound or at pin sites occurs after external fixation, even if it is treated successfully, its recurrence after subsequent IMN is possible. In planning treatment for a tibial fracture, the surgeon should remember the problems that may result from external fixator pins placed in the tibia before IM nails.
Tornetta and DeMarco have postulated that nailing after external fixation can be separated into early cases, done by protocol as planned “sequential” treatment, and later “reconstructive” cases. Problems with infection are more likely in the reconstructive setting and should be less frequent if IMN is avoided when pin wounds have been infected or heavily contaminated. Overall, if done in the first 2 weeks after external fixation, revision to IM nails appears to be safe a procedure with minimal morbidity.
Plating of Closed Tibia Shaft Fractures
Plating of fractures of the tibia first became popular during the 1950s and led to many complications. It has been recognized that good results after plating of tibial shaft fractures are dependent on meticulous soft tissue handling and surgical expertise. Proper patient selection is also important. Crushed soft tissues, tenuous skin flaps, severe open wounds, and other signs of high-energy trauma may portend a high rate of complications if open reduction and internal fixation (ORIF) with plates and screws is chosen. Plating can be made considerably safer by waiting until the soft tissues have recovered. Temporization can be performed with external fixators placed outside the planned incision for plating. Minimally invasive plating techniques that decrease iatrogenic surgical trauma may reduce soft tissue complications. The surgeon tunnels a plate extraperiosteally under intact skin and places screws through small incisions with image intensifier control. However, unless the overlying skin is healthy and handled gently, complications may still occur. Because less soft tissue stripping is required with minimally invasive techniques that spare the muscle and periosteum, blood supply to the fracture site is better preserved. However, percutaneous, submuscular plating is technically demanding and must be performed by experienced surgeon aware of the complexity of this technique.
Plates can be used for rigid fixation and absolute stability when fracture comminution is minimal. In these cases, an open reduction with a relatively large skin incision is not absolutely necessary but may be required. Percutaneous plate fixation techniques can be used for relative stability to induce callus formation and potentially more rapid healing in patients with multifragmentary fractures.
Plate fixation of closed tibial fractures may be used occasionally after arterial repair, particularly if the needed exposure has been created during the approach to the injured vessels. However, plates should be used with great caution in open fractures requiring vascular repair because of especially high infection rates. In this setting, external fixation is generally preferred.
In fresh tibial injuries, plates are probably best suited for proximal and distal displaced fractures that involve the articular surface and require more stability than can be provided by lag screws alone or when there is a total knee replacement precluding IM fixation. In low-energy injuries, when used with good technique, their results can rival those of IM nails, although patients may have to wait longer before significant weight bearing. Technical aspects of plate fixation are covered in other sections of this book.
Surgical Approaches.
With its triangular external cross section, the tibial shaft offers three potential surfaces for plate application. The medial and lateral surfaces are readily available from an anterior approach. The less accessible posterior surface may also be mechanically less satisfactory for plate fixation ( Fig. 64.16 ).
It is crucial to assess the condition of the skin and soft tissues carefully before choosing plate fixation and before exposing the tibia. The subcutaneous anteromedial surface of the tibia is often injured, and it may not be suitable for plate application, especially after direct local trauma. There is a high risk of wound slough if an incision is made near or through contusions, lacerations, or abrasions. For this reason, many believe that the anteromedial surface should rarely, if ever, be used for acute tibial fractures. A safer alternative may be the anterolateral surface, which is covered by the anterior compartment muscles, although a plate applied here interferes with an important route of blood supply to the healing fracture. Thus each injured leg should be evaluated on the basis of its own characteristics and those of the injury. The presence of a posteromedial incision for vascular repair or fasciotomy provides easy access to the medial surface of the tibia, which might also be the best site for a plate if extensive soft tissue wounds mandate from the outset the use of a muscle pedicle flap for medial coverage. In such a situation, there seems to be little merit to detaching any remaining anterior compartment muscles from the bone fragments. An anterolateral incision risks slough of the intervening skin flap if it is combined with one on the posteromedial leg.
The tibia is approached with the patient supine. A thigh tourniquet should be used cautiously because there may be an increased incidence of wound problems. The leg is prepared sterilely and draped free on the standard or radiolucent operating table. Additional padding under the ipsilateral buttock may aid access to the lateral calf.
The same skin incision can be used to access both the anteromedial and anterolateral tibial surfaces. This incision should be made over the muscles of the anterior compartment at least 1 cm lateral to the anterior tibial crest (see Fig. 64.16 ). If there is significant soft tissue contusion, a more lateral incision ensures that bone and hardware will remain covered by soft tissue, even if skin closure is not possible. Similarly, a posteromedial incision can be used to access the tibia's anteromedial surface. The incision is carried down directly through the deep fascia without creating subcutaneous flaps. Preservation of a fasciocutaneous flap composed of skin, subcutaneous tissue, and underlying deep fascia is important because the dermal blood supply depends on vascular connections with the fascia. The resulting anterior flap is elevated from the underlying muscles and reflected only as much as required for exposure. A longer incision is safer than overvigorous retraction. Self-retaining retractors should be used briefly and gently or not at all.
Depending on the surgeon's choice, the tibial shaft is next exposed on either its anterolateral or anteromedial aspect. To preserve blood supply, only minimal soft tissue should be reflected from the other surface. The tibia can be exposed either subperiosteally or extraperiosteally. Fracture healing after plate fixation appears to be equivalent with either exposure.
Minimally Invasive Approaches.
The tibial shaft can be plated using minimally invasive approaches. These approaches minimize soft tissue stripping and preserve blood supply to the fracture site. Either a proximal anterolateral approach or a distal anteromedial approach is typically used. A more detailed description of the minimally invasive technique is available in the sections on proximal and distal tibial shaft fractures.
Reduction Techniques.
Reduction techniques can be either under direct visualization or with the use of fluoroscopic imaging. Direct visualization may be easier but is often traumatic to the soft tissues surrounding the fracture site in the area of already compromised muscle and skin. Minimally invasive, submuscular, extraperiosteal fracture reduction is more technically demanding and may need fluoroscopic imaging and the AO distractor or an external fixator to aid in controlling length, rotation, and alignment ( Fig. 64.17 ). Another indirect reduction technique involves attachment of an appropriately contoured plate to one major fragment, with which it can be manipulated relative to the other, often with the aid of the articulated tension device or a bone spreader and screw.
Fixation Technique.
The most common plate for most diaphyseal tibial fractures is the 4.5-mm compression plate. A tibial plate should be sufficiently long that at least four secure screws attach each end to the proximal and distal fragments. A longer plate with at least three bicortical screws can increase stability. Increasing the span between the most distal and most proximal screw improves stability more than can be obtained by using more screws in a shorter span. One must be cautious about undisplaced comminution. Locking plates are rarely needed for the fixation of tibial shaft fractures. When used, they are typically of the “periarticular” type and in cases where a minimally invasive approach is used. Osteoporotic bone can be an indication for using locking plates. The use of these plates is described in the sections on proximal and distal shaft fractures.
Plate Length and Screw Density.
Bridge plates with angular stable screws should be at least three times longer than the fracture zone. Three cortical screws on either side of the fracture may be sufficient with two screws close to the fracture and one distant to the fracture. Plates with expanded metaphyseal area, and the selection of locking head screws, may be advisable for short periarticular segments and for osteoporosis. Unicortical locking head screws gain less fixation as bicortical screws of the same diameter and should be used sparingly.
External Fixation.
External fixation for closed tibial shaft fracture is done similarly to open fractures and is described later in that section.
Pitfalls and Avoidance of Complications.
Adequate radiographs of the injured limb are needed to ensure that the fracture is suitable for IMN and to identify fracture propagation into the knee or ankle. Occasionally an undisplaced metaphyseal fracture can be fixed with lag screws before IMN. When there is marked comminution of the tibia and fibula, making radiographic interpretation difficult, then measuring the uninjured limb is essential. Measurement via a measuring tape from the apex of the tibial tubercle to the tip of the medial malleolus is a preliminary guide to tibial length and leg length. It may be more accurate than using a radiographic ruler or templates. Radiographic determination of medullary canal diameter can be unreliable and better measured with an IM reamer or a “sound” of known outside diameter.
The surgeon should review and know the technical details of the selected implant system. It is critical to know the available length and diameter of the nails and the locations of locking screw holes and proximal and distal bends. It is also crucial to know the length and width of the available plates. Careful inspection of the patient's uninjured leg is helpful as a guide to correct alignment, particularly rotation (e.g., foot–thigh angle with the knee at 90 degrees and bimalleolar angle). Preoperative images of the AP or lateral uninjured knee and ankle can also be taken without moving the leg and compared with intraoperative images of the injured leg to assess for rotational malreduction of the tibia.
Wounds are usually closed primarily, and suction drains may be used as clinically decided by the surgeon. When performing an open reduction, the fascia should be left open to decrease the risk of compartment syndrome. Should one side of the wound be more tenuous, it may be appropriate to use Algöwer's modified Donnati stitch, passing only through subcuticular tissue on the side at greater risk. After application of a sterile dressing and adequate padding, the foot and ankle are splinted in neutral, and the leg is moderately elevated during the initial postoperative period. Prophylactic antibiotics are generally discontinued within 24 hours after ORIF of a closed fracture.
Postoperative Care and Rehabilitation After Plating.
Patients are much more comfortable in a splint than with the foot and ankle free after fixation of all but the most proximal tibial fractures. Moreover, equinus contracture can be avoided if the ankle is positioned in plantigrade in the splint until swelling has decreased and physical therapy can begin. Early motion, if desired, may begin within a few days. A splint or Velcro boot is helpful between exercise sessions for comfort and to keep the ankle in plantigrade.
Assessment of Healing.
Union of a tibial fracture is assessed using clinical and radiographic parameters. There is progressive bone remodeling with eventual obliteration of the fracture zone over many months after union has been achieved. Conventionally, union is diagnosed when there is no pain or tenderness at the fracture site and at least three cortices are bridged by bone on AP and lateral radiographs. AP and lateral radiographs are standard for monitoring alignment of tibial fractures, but the addition of both 45-degree oblique views aids in the evaluation of healing. Union is also evident when a patient can bear weight on the fractured tibia without pain at the fracture site. CT may be helpful but may not be conclusive relative to well-exposed standard films and may occasionally show false positives (specificity of 62%). If the tibial fracture is not united 6 months after surgical or nonsurgical treatment, radiographs are performed at 1-month intervals to see if there is progression of healing at the fracture site. If there is progressive healing, surgical intervention for a nonunion may be avoided. If there is no progression of healing 9 months after fracture treatment began, a nonunion is diagnosed. Strain gauges attached to external fixator pins can be used in the laboratory to document bending stiffness, the mechanical property assessed manually by the clinician as “fracture site stability.” Using such strain gauges, Richardson and coworkers demonstrated that sagittal plane stiffness of 15 Nm/degree is a threshold that defines tibial fracture union. Overall, it is difficult to assess fracture healing from a single set of radiographs. Hammer and coworkers showed this clearly for tibial fractures. The patient's serial films over 3 months should be reviewed carefully for signs of problems or progression of healing. Problems can be in the form of progressive deformity, hardware failure, lack of maturing callus, and an increasingly evident fracture cleft.
Anatomic reduction and interfragmentary compression are hallmarks of rigid internal fixation. If achieved, the fracture line may not be evident on the initial postfixation radiographs. Fractures thus fixed with absolute stability exhibit minimal external callus formation. In this situation, healing must be diagnosed primarily by the absence of pain and absence of radiographic signs of instability (e.g., external callus, loss of fixation, or bone resorption around implants) as the patient progresses from non–weight-bearing to full weight-bearing activity over an appropriate time period, according to the surgeon's judgment and experience. Because internal fixation does not accelerate union, 3 or more months must typically be allowed before unrestricted activity can be allowed.
Key Points: Postoperative Care for Closed Tibial Fractures
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If the tibial fracture is not united 6 months after surgical or nonsurgical treatment, radiographs are performed at 1-month intervals to see if there is progression of healing at the fracture site.
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If there is no progression of healing 9 months after fracture treatment began, a nonunion is diagnosed.
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Removal of locking screws to accelerate healing (so-called dynamization) has not been proven to increase union rates significantly. Removal of asymptomatic nails may be considered optional.
Postoperative Care
Moderate elevation and observation for increasing pain and neurovascular problems are necessary for the first 1 or 2 days. After the initial postoperative period, the patient is encouraged to ambulate with crutches or a walker if possible. Weight bearing may be allowed with larger diameter (reamed) nails and locking screws if the fracture configuration is stable and there is bone contact that shares axial loading. If stability is uncertain, only limited weight bearing is allowed, typically until about 6 weeks when soft tissues and fibula are usually healed enough to prevent loss of alignment or excessive hardware stresses with tibial fracture loading. Some form of prophylaxis against venous thromboembolic disease is appropriate, particularly if the patient has any risk factors. How much (if any) anticoagulation is appropriate for patients without risk factors, and its duration, remains controversial. Mechanical devices may be used on uninjured parts (foot or contralateral leg).
Weight Bearing.
IM nails vary significantly with regard to strength and stiffness depending on diameter and cross-sectional design. Tibial anatomy also varies from person to person and from one location to another. These factors, in addition to the wide spectrum of tibial fracture configurations, make it essential to individualize postoperative care for patients with nailed tibial fractures.
When the nail acts primarily as a gliding splint and bone contact allows the tibia to bear compressive loads, full weight bearing can be allowed as soon as the patient can tolerate it. If comminution or poor contact is present, then significant weight bearing must be deferred to prevent failure of fixation. With early and progressive healing, as revealed by periodic radiographs, weight bearing can be increased progressively. At a minimum, knee, ankle, and foot exercises should begin for all patients as soon as possible in the postoperative period to prevent decreased ROM at these joints. The patient should not sit with the leg dependent for the first few weeks. Instead, it should be elevated above the heart when the patient is not walking.
Outpatient Care.
Patients with isolated tibia fractures can be treated as outpatients once pain is managed with oral medications; they are ambulatory; and there is no evidence of compartment syndrome, skin problems, or increasing pain. Instructions are provided for bracing and non–weight-bearing activity as detailed previously. Follow-up visits are needed at regular intervals until the fracture is healed and the limb rehabilitated. Robertson and colleagues found that patient management was not affected by radiographs obtained during the first 10 weeks after IMN. Therefore an initial radiograph is needed postoperatively to assess initial fixation and alignment and then after 6 weeks. Thereafter, radiographs at least every 6 weeks should be monitored for bridging callus, which will determine weight-bearing and physical therapy prescriptions. Oblique views, as well as AP and lateral views, may be valuable to assess fracture healing. When bridging callus is evident and after the fibula has healed, there is usually little reason to be concerned about persistent, slowly healing fracture lines. If a nonunion is diagnosed, it may be wise to change to a larger reamed nail and/or bone graft. The timing of such a rarely needed procedure is adjusted according to the estimated durability of the patient's nail.
Nail Removal.
Removal of locking screws to accelerate healing (so-called dynamization) has not been proven to increase union rates significantly. In spite of intraoperative efforts to prevent it, the tibial fracture site may remain distracted after IM nail fixation. If observed during nailing, this should be remedied by compressive backslapping after distal locking. Rotation must be controlled during this part of the procedure and then checked before locking.
Symptoms at the insertion site are common with or without nail prominence. Some patients may have a resolution of knee pain after the nail removal. Many patients may request nail removal when so informed. Removal of asymptomatic nails may be considered optional. The surgeon must discuss with the patient the possibility of nail incarceration during extraction. Nail designs that make extraction difficult include slotted nails and nails with a distal bend. However, removal at a convenient time after healing can be a reasonable option for symptomatic younger patients and those with prominent hardware, with an acceptably low rate of complications.
Before hardware removal, the surgeon must correctly identify the type of implant and obtain the necessary instruments for nail extraction. The manufacturer's instructions should be reviewed preoperatively because instrumentation might be used differently during removal than during insertion. Different methods have been described for nail removal when the nail extraction instrumentation is unavailable or cannot be used due to a damaged nail. Particular attention must be given to broken or bent nails, broken screws, and older nail designs. Occasionally, IM nail removal may prove so difficult that a longitudinal osteotomy of the entire diaphysis is required to extract the nail without excessive force. The patient must be aware of complications that may occur from the removal of a nail preoperatively. These include retained hardware, continued knee pain, refracture, intraoperative fracture, infection, and failure of the procedure to remove the nail or pain.
Rehabilitation After Plating.
Properly performed plate fixation for tibial fractures should provide sufficient stability for the motion of adjacent joints and myotendinous units. This helps prevent stiffness, particularly if it is combined with the use of resting splints in ankle dorsiflexion. However, it is essential to delay significant weight bearing on the plated tibial fracture until healing is advanced enough to protect the fixation from cyclic loading and resulting failure. Optimally, this means limited weight bearing on crutches, using only an elastic stocking as needed to control edema. However, when patient cooperation is questionable or fixation is tenuous, additional external support is advised. In the most unreliable patient, this might be a long leg cast with the knee flexed and the dorsum of the foot portion removed to permit ankle dorsiflexion above neutral. A functional cast or fracture brace could be employed, but these may not provide enough protection for the bone–plate construct and are perhaps too easily discarded by the patient.
Periodic outpatient follow-up is required until the fracture is healed and the patient rehabilitated. The patient is instructed to report promptly any increase in pain or wound problems. Unless problems are noted, radiographs are needed only every 4 to 6 weeks until union is achieved. No weight bearing is allowed during the first 6 weeks. Weight bearing can be gradually increased during the second 6 weeks after fracture if radiographs demonstrate maintenance of fixation and progressive obliteration of any fracture lines. Weight bearing should increase slowly after more severe injuries with increased fracture comminution and/or soft tissue compromise.
External callus is rarely seen with rigid internal fixation in short oblique, spiral, or transverse fractures treated with lag screw technique or compression plating (absolute stability). However, callus formation can be expected with bridge plating in fractures with comminution (relative stability). If healing of a plated tibial fracture does not progress over 3 to 6 months, serious consideration should be given to early revision of fixation, rather than delaying necessary surgery while the tibia becomes more osteoporotic. Ankle and subtalar ROM exercises should begin early after plating of a tibial fracture to minimize late disability resulting from contractures of the ankle joints. Low-resistance strength and endurance exercises are progressively increased as the fracture heals, and functional rehabilitation is completed once bone healing and soft tissues permit. By 4 or 5 months, most plated tibial fractures are healed enough for unsupported weight bearing. Rarely is it wise for the patient to return to contact sports and risky activities in less than 6 to 9 months. Time estimates for tibial fracture healing increase with more severe injuries. Clinical and radiographic progress of healing is continually critically reassessed to ensure that union is complete before excessive loading is begun. Local pain, warmth, swelling, and tenderness may indicate mechanical instability or occult infection. Adequate radiographs, wound aspiration, sedimentation rate, C-reactive protein, and perhaps indium-labeled leukocyte scans may be helpful for distinguishing infection.
Plate Removal.
Hardware removal should be delayed at least 18 months or more for severe injuries. Dual-energy x-ray absorptiometry (DXA) studies have shown that there is no progressive decrease in bone density under tibial plates in current use, as can occur in stress-protected proximal femurs with some total joint implants. Incomplete healing of severe fractures, continued remodeling of necrotic bone, and the temporary stress-riser effect of recently removed screws all predispose to refracture after hardware removal. Delay until completion of both bone union and remodeling, with protection from undue stress for 6 to 12 weeks after plate and screw removal, is important to minimize the risk of refracture.
Closed Proximal Third Tibial Fractures
Extraarticular proximal third tibial fractures are often the result of a high-energy mechanism. Fractures of the proximal third constitute about 2% to 11% of all tibial shaft fractures. These fractures are challenging because of their severity. They have an increased frequency of compartment syndrome, neurovascular injury, and damage of the soft tissue envelope. Moreover, proximal third tibia fractures are more difficult to reduce and fix with nails. Because of variable precision in entry-site location and a mismatch between the diameter of the nail and the proximal tibia, less stable fixation may occur in the larger diameter proximal metadiaphyseal region. Earlier than 2000, IM nails were less successful at controlling proximal third tibial fractures. However, through the study of proximal tibial anatomy and modification of nailing techniques, there has been an increase in accuracy of reduction and maintenance of that reduction with IMN. To obtain and hold reduction during nailing of a proximal fracture, an optimal starting point, a unicortical plate, a distractor, and possibly Poller screws might be considered, separately or in combination. An alternative to nailing is minimally invasive plate fixation, with small incisions and specially designed plates. This technique offers the mechanical benefits and deficiencies of plating, with less soft tissue and bone healing problems than found with an open procedure. When comparing nailing to plating, one must take into consideration the soft tissue envelope and the stability of the construct. Open plating is hazardous because of iatrogenic traumatization of already distressed muscle and skin. Minimally invasive submuscular plating is a better option than open plating procedures and has been shown to decrease the rate of infection and nonunion of proximal third tibia fractures. Nailing, however, is IM and is completely soft tissue sparing. Moreover, because the nail is within the anatomic axis of the tibia, forces, micromotion, and strain are essentially distributed evenly on the medial and lateral aspects of the nail. A plate that is placed laterally will have increased motion and strain on the medial aspect of the tibia because it is lateral to the anatomic axis of the tibia. This causes increased strain on the medial side of the fracture that may or may not lead to too much instability for bone healing.
Key Point: Surgical Treatment of Closed Proximal Third Tibial Fractures
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To obtain and hold reduction during nailing of a proximal fracture, an optimal starting point, a unicortical plate, a distractor, and possibly Poller screws might be considered, separately or in combination.
Emergent Treatment
The initial treatment of proximal tibial shaft fractures is similar to that for midshaft fractures and includes splinting, icing, and elevation of the injured limb. Particular attention to soft tissue compromise in anterior skin should be given. Special attention should be given to the risk of compartment syndrome.
Indications for Definitive Care (Surgical Versus Nonoperative Care)
Proximal tibial shaft fractures are notoriously difficult to treat nonoperatively. It can be difficult to obtain and maintain reduction of these fractures in a cast. In one prospective study of 50 conservatively treated tibial fractures, the rate of malunion was 75% in proximal and distal extraarticular tibia fractures and 25% in midshaft fractures.
Nonoperative Treatment
The nonoperative treatment of proximal third tibial shaft fracture does not significantly differ from that of tibial midshaft fractures.
Surgical Treatment
Surgical fixation of proximal tibia fractures can be accomplished with plate osteosynthesis, IMN, and external fixation. The goals of these techniques are restoration and maintenance of length, mechanical alignment, and rotation. Fixation should be sufficient to allow early ROM of the knee and ankle. External fixation is usually reserved for high-energy injuries with significant soft tissue compromise as a temporization method. A recent retrospective clinical study found that treating proximal tibial shaft fractures with IMN or plating yielded similar results, with a tendency of IM nails to need more procedures to achieve adequate reductions and with plates needing more hardware removal. In a biomechanical study comparing various fixation constructs for proximal tibia fractures, reamed nails were found to withstand the highest axial loads and were superior to plates but not to external fixators and hybrid constructs in withstanding bending forces. There were no differences between constructs in rotational stiffness.
Surgical Anatomy
The triangular bony architecture of the proximal tibia consists of a wide metaphyseal region that narrows distally to form a well-defined cortical tube. In addition, the central axis of the tibial shaft is slightly lateral to the midline of the epiphysis, and the AP width of the shaft is narrower medially. Knowledge of this bony architecture is especially important for nailing of proximal tibias. In the patient with a proximal tibia fracture, there is nail–bone mismatch, with the nail much smaller than the inner diameter of the tibia. Therefore the nail may not be able to maintain proximal fragment alignment. If the starting point is located too far medially, the inner medial tibial metaphyseal cortex acts as a chute that deflects the nail laterally, causing valgus malalignment.
There are many muscular forces that act on the proximal fragment to cause malalignment. The patellar tendon inserts on the tibial tubercle and pulls the proximal fragment into extension while the hamstring tendons pull the distal fragment into flexion and the gastrocnemius muscle shortens the fracture. The pes anserinus inserts anteromedially on the proximal fragment, and the anterior compartment muscles originate on the anterolateral proximal tibia. The force exerted on the tibia by these attachments contributes to valgus and apex-anterior deforming forces.
Intramedullary Nailing of Proximal Tibia Shaft Fracture
Some studies of proximal third tibia fracture IMN illustrated that there may be an increase in malreductions. Malalignment after nailing typically consists of apex anterior and valgus angulation and is often accompanied by posterior displacement of the distal fragment. Freedman and Johnson reported malalignment (i.e., angulation deformity >5 degrees in any plane) in a radiographic study of 133 cases managed with tibial nailing. Malalignment was found in 58% of proximal third tibia fractures compared with 7% and 8% in middle and distal third fractures, respectively. Other studies have reported malalignment rates ranging from 44% to 84%.
However, contemporary implant designs and improved surgical techniques have decreased the rates of malreduction in proximal third tibia fractures. Recent studies demonstrated that most extraarticular proximal and some of the simple intraarticular proximal tibia fractures can be treated with IM nails. Specific surgical techniques that help to minimize complications after IMN of proximal tibia fractures include careful attention to nail insertion portal placement and insertion technique, as well as judicious use of Poller screws, provisional mini-plating, and temporary external fixation constructs.
Deforming factors that are in play when nailing a proximal tibia fracture include the “wedge effect,” in which the proximal bend in the nail acts as a wedge, pushing the distal fragment distally and posteriorly. A second deforming force is the pull of the patellar tendon on the short proximal fracture fragment. The third factor is a medial starting point in the proximal tibia, which narrows the effective diameter of the tibia, causing anterior displacement and excessive valgus.
An apex-anterior angulation deformity may be caused when the knee is flexed to gain access to the entry portal. This deformity may be avoided by careful entry site selection, which is usually anterior to the lateral intercondylar eminence or in line with the IM canal of the tibia in the midshaft. This may be easier with an incision lateral to, or through, the patellar tendon rather than medial to it. The entry point is then extended into the IM canal in the anterior third of the tibia parallel to the anterior cortex of the proximal fragment. Insertion in the flexed position and then locking in the extended position can aid in maintaining reduction.
Nailing Proximal Tibial Fractures in a Semi-Extended Position.
Semi-extended tibial nailing was initially developed for greater ease of reduction and imaging, mitigating many of the challenges associated with flexed-knee IMN. Various incisions for semi-extended tibial nailing have been described, including lateral and medial knee arthrotomies, suprapatellar IM nail insertion, and extraarticular parapatellar approaches.
Reduction Techniques
External Fixation Assisted Nailing.
Buehler and colleagues suggested the use of a universal distractor during nailing in flexion. They used an AO distractor medially, correcting any posterior displacement of the diaphyseal fragment with traction and a manipulating Schantz screw or clamp. They proposed creating the entry site with the knee in hyperflexion ( Fig. 64.18 ). The entry portal in the proximal segment is anterior to the lateral eminence on the AP view and is confirmed radiographically on the lateral view to start at the anterior edge of the articular surface and to progress parallel to the anterior cortex of the proximal fragment. This helps avoid posterior displacement of the distal piece caused by impingement of the nail's proximal bend on the posterior cortex of the distal segment. The distal and posterior displacements can be avoided by selection of a proper entry path. The recommendations for entry and reduction included the following:
- 1.
AO femoral distractor placed on medial tibia
- 2.
Correct overlapping posterior walls, with distraction and Schantz screw if needed
- 3.
Proximal and lateral starting point in line with the lateral intercondylar eminence
- 4.
Hyperflexion of the knee for nail insertion
- 5.
Sagittal plane entry point parallel to the anterior cortex of the proximal fragment under radiographic control
- 6.
Proximal interlocking with knee in full extension
Alternately, an external fixator can be used to achieve and maintain length, rotation, and coronal alignment. This technique uses a centrally threaded 6-mm-diameter external fixation pin placed from lateral to medial in the proximal fragment and parallel to the tibial plateau ( Fig. 64.19 ). Another centrally threaded 6-mm-diameter external fixation pin can be placed in the calcaneus or distal tibia from medial to lateral parallel to the tibial plafond. Two bars are then connected to the pins, and length, rotation, and alignment in the coronal plane are achieved. A pin can be placed into the anterior aspect of the proximal fragment, making sure not to interfere with the future nail path. This pin can then be attached to the external fixator to counteract procurvatum of the proximal fragment. The knee can then be hyperflexed to achieve entry into the tibia anterior to the lateral intercondylar eminence and in the anterior third and parallel to the proximal tibia. With more contemporary short tibial targeting jigs, the knee can be extended after nail insertion and the proximal fragment locked in that position with two or more nonparallel screws.
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