Fractures of the Tibial Pilon

The defining characteristic of a pilon fracture is the involvement of the distal tibial metaphysis and articular block extending 5 cm proximal to the tibiotalar joint. The nature and complexity of these fractures range from simple patterns (e.g., boot-top ski injuries) to complex, high-energy injuries with significant soft tissue stripping, fracture comminution, articular impaction, and bone loss. At least half are due to motor vehicle collisions. Therefore it is not surprising that one-third to one-half of patients who sustain a pilon fracture have concomitant extremity fractures or injuries involving multiple organ systems. Additionally, the soft tissue component of the injury is of critical importance, with 10% to 50% presenting as open fractures. Even when closed, surgeons often view these fractures as primarily a severe soft tissue injury with an associated intraarticular fracture. This rationale had guided the current common protocol of initial external stabilization and delayed reconstruction techniques.

Treatment is fraught with complications, including infection, nonunion, malunion, and posttraumatic arthrosis. Fortunately, these injuries account for only 3% to 10% of all tibia fractures and 1% of all lower extremity fractures. The goal of this chapter is to review typical fracture characteristics, common current treatment protocols, surgical techniques, and complications associated with pilon fracture care.

Mechanism of Injury

Pilon fractures most commonly occur in motor vehicle collisions, falls from height, and sporting accidents. High-energy injury mechanisms impart tremendous force to the lower extremity. The increasing frequency of high-energy injuries may be related to improved vehicle safety features, such as air bags, which have contributed to increased patient survival. This has led to efforts to redesign vehicle passenger compartment structures, including the toe pan, to protect the lower extremities. Encouragingly, recent data indicate a potential trend of reduced lower leg injuries.

Pilon fractures result from two different force types that can either act individually or concurrently. The primary force is axial compression, resulting in the talus being driven into the tibial plafond; this frequently results in concomitant damage to the talar dome. The secondary force type is rotation, and it produces variable degrees of articular shearing and fracture fragment displacement. A clear distinction should be made between these two different forces because the relative contribution of each affects the severity of the fracture, soft tissue damage, and prognosis. For example, high-energy injuries tend to be associated with a greater degree of axial compression, resulting in more articular impaction, metaphyseal comminution, and severe soft tissue disruption. The significant forces during axial compression have also been shown to cause cartilage necrosis that may be partially responsible for poor clinical outcomes after treatment despite anatomic radiographic articular reconstruction. In contrast to high-energy injuries, lower-energy injuries commonly involve rotational forces. These occur most often during sporting accidents, such as skiing (e.g., boot-top fracture).

Several authors have also emphasized the importance of foot position at the time of injury as it relates to the fracture pattern ( Fig. 65.1 ). If the foot is plantar flexed, the posteriorly directed compressive forces result in separation of a large posterior plafond fragment (see Fig. 65.1A ; also see Figs. 65.14 and 65.15 ). With a neutral foot, axial compression results in the creation of a common Y-shaped articular fracture pattern with large medial, anterolateral, and posterolateral fragments ( Fig. 65.2 ; see Figs. 65.1B, 65.11, 65.13, and 65.18 ). A dorsiflexed ankle position results in the broader anterior talar body causing compression of the anterior tibial plafond, producing an anterior fracture fragment with a variable degree of articular impaction (see Fig. 65.1C ; also see Fig. 65.20 ).

$Fig. 65.1, Mechanism of injury. Ankle position as it relates to fracture pattern. (A) A plantar flexion injury results in a posterior lip fragment. (B) A neutral ankle injury results in anterior and posterior fragments. (C) A dorsiflexion injury results in an anterior lip fragment.$

$Fig. 65.2, (A) Axial computed tomography (CT) scan. Classically, the major components of the pilon fracture that can be identified are the anterolateral (Tillaux–Chaput) fragment, the posterior (Volkmann triangle) fragment, the medial malleolus, and a variable degree of comminution and impaction of the articular surface (die punch). Axial CT images of another patient before (B) and after (C) reduction and placement of a spanning external fixator, demonstrating the additional information provided by obtaining the postreduction CT scan.$

An associated fibula fracture is present in approximately 70% to 85% of cases, with one study noting a 100% rate in posterior pilon fractures. The presence of a comminuted fibula fracture typically results from a valgus force, producing articular impaction of the lateral tibial plafond and a greater likelihood of axial malalignment because of the absence of an intact lateral column. Open fractures are also more commonly associated with initial valgus displacement (see Figs. 65.27, 65.30, and 65.31 ), primarily related to thinner medial soft tissues. An intact fibula is more likely to be associated with a varus force, with resulting medial tibial articular surface impaction, and possibly a less severe injury (see Figs. 65.20 and 65.21 ), although open fractures occur in this setting as well (see Fig. 65.20C ). A recent study compared pilon fractures with and without an intact fibula and found that partial plafond fracture patterns and less articular comminution occurred more often in patients with the latter. However, significant lateral impaction with axial loads can still occur despite an intact fibula (see Fig. 65.12 ).

Key Points

Pilon fractures most commonly occur by high-energy injury mechanisms.
If the foot is plantar flexed, the posteriorly directed compressive forces result in separation of a large posterior plafond fragment.
With a neutral foot, axial compression results in the creation of a common Y-shaped articular fracture pattern with large medial, anterolateral, and posterolateral fragments.
A dorsiflexed ankle position results in the broader anterior talar body causing compression of the anterior tibial plafond, producing an anterior fracture fragment with a variable degree of articular impaction.

Classification

Classification systems ideally help a clinician efficiently convey the characteristics and severity of a particular fracture as well as provide some guidance on the preferred treatment and prognosis of the injury. Although numerous pilon fracture classifications exist, the Ruëdi and Allgöwer and Arbeitsgemeinschaft für Osteosynthesefragen (AO)/Orthopaedic Trauma Association (OTA) are the two most commonly used.

The classification system proposed by Ruëdi and Allgöwer ( Fig. 65.3 ) in the late 1960s is descriptive and makes a distinction between nondisplaced, low-energy injuries and severely comminuted and impacted fractures. A Ruëdi type I fracture is a cleavage fracture of the distal end of the tibia without significant displacement of the articular surface. A type II fracture has a significant displacement of the articular surface cleavage lines, but the joint surface is neither impacted nor grossly comminuted. The more severe type III fracture has both comminution and impaction of the distal tibial articular surface and the supporting metaphysis.

$Fig. 65.3, Ruëdi and Allgöwer's classification of pilon fractures.$

The current AO/OTA classification ( Fig. 65.4 ) is the most descriptive system in the literature. Fractures of the distal end of the tibia are assigned the number 43 and divided into extraarticular fractures (type A), partial articular fractures (type B, Fig. 65.5 ; see Figs. 65.12, 65.14, 65.15, 65.20, 65.30 ), and complete articular fractures with metaphyseal-diaphyseal dissociation (type C, see Figs. 65.8 to 65.11, 65.15, 65.16, 65.18, 65.22, 65.24, 65.26, 65.28, 65.30, and 65.31 ). Fracture types are further subdivided into three groups (1, 2, and 3) depending on the presence of articular and metaphyseal comminution and impaction.

$Fig. 65.4, (A–C) The comprehensive Arbeitsgemeinschaft für Osteosynthesefragen (AO)/Orthopaedic Trauma Association (OTA) classification system for distal tibial fractures including the pilon (types B2, B3, and C). The tibia is bone 4. The pilon region is its segment 3. Thus 43 is the numerical locator for pilon fractures.$

$Fig. 65.5, (A–C) Displaced AO type B2 pilon fracture with shortening and dislocation of the talus from the anterior portion of the articular surface. The talus is displaced with the posterior fragment. This is a transitional fracture between an ankle fracture and a true pilon fracture. (D) A radiograph taken with external rotation better delineates the large medial malleolar fracture with extension into the metaphysis (white arrowhead) . (E and F) A computed tomography (CT) scan identifies areas of comminution (black arrows) . (G) Reduction was performed through a small anteromedial exposure on postinjury day 4. Because of the simple articular pattern and metaphyseal nature of the fracture, only a thin one-third tubular plate and screws were required for stable fixation. Proper positioning of the plate blocks (buttress or antiglide mode) proximal displacement of the medial fragment and allows the insertion of interfragmentary lag screws perpendicular to the fracture plane through the plate for increased stability. (H) The patient had minimal pain and excellent function at 8-month follow-up.$

Unfortunately, poor to moderate interobserver and intraobserver reliability of both the AO/OTA and Ruëdi-Allgöwer classification systems have been observed. The AO system is reliable when classifying by type (A, B, C), but agreement becomes poor when it is used to further subdivide fractures into groups (1, 2, 3). Although experience may improve the ability to more consistently classify pilon fractures, its effect has not been shown to be significant.

Although surgeons cannot consistently agree on the classification of specific fracture patterns, there is a high correlation with respect to assessing the severity of the injury and the quality of a good or poor reduction. DeCoster and coworkers found 94% agreement among surgeons when ranking the severity of the injury to the articular surface, 89% agreement when ranking the severity of the overall fracture and the quality of the articular reduction, and 88% agreement when ranking the overall reduction.

Radiographic Evaluation

Pilon fracture treatment requires a clear understanding of the fracture. Evaluation begins with three standard views of the ankle: anterior-posterior (AP), mortise, and lateral. Although rarely required, a 45-degree external rotation oblique view may be helpful for further evaluating the anterolateral and posteromedial tibia (see Fig. 65.5D ). Traction radiographs, after application of an external fixator, often allow better visualization of individual fracture fragments. For complex fractures, mortise and lateral radiographs of the contralateral ankle can also provide a helpful comparison during preoperative planning and intraoperative stabilization.

Most authors agree that preoperative computed tomography (CT) scanning provides valuable fracture pattern information. It can be especially helpful in identifying the location and orientation of all fracture lines and the extent of articular comminution and impaction (see Fig. 65.2 ; also see multiple cases in this chapter). It is also particularly valuable when there are extensive posterior fracture patterns because standard radiographs can often underestimate fracture fragment size. Standard radiographs can also fail to identify rotational or translational displacement of osteochondral fragments as large as 5 mm. On an AP radiograph, complex posterior pilon fracture patterns can often be distinguished from a simple posterior malleolar rotational ankle fracture by the presence of a characteristic double-contour sign representing a medial metaphyseal spike (see Figs. 65.5B and D and 65.14 ). This indicates the existence of an additional posteromedial fracture fragment and the involvement of the majority of the posterior plafond. Recognition of a large posteromedial fragment is important because failure to address it may lead to chronic posteromedial talar subluxation. One final advantage of preoperative CT imaging is the ability to evaluate for displacement and entrapment of soft tissue structures. Two recent CT pilon imaging studies found that peroneal tendon displacement and posteromedial soft tissue entrapment occur in 11% to 19% of pilon fracture cases, respectively. Recognition of a soft tissue abnormality can change the surgical plan and should be assessed in every case.

A CT scan should be obtained before definitive fixation to assist with preoperative planning. It is ideally performed after the application of an external fixator when image interpretation is easier because of improved fragment alignment through ligamentotaxis (compare Fig. 65.2B and C ). A properly oriented CT scan will often assist the surgeon in making specific preoperative decisions about optimal incision location and hardware position (see Figs. 65.9, 65.11 to 65.13, and Fig. 65.16 ; also see Figs. 65.5, 65.10, 65.18, 65.20, 65.24, and 65.31 ). Tornetta and Gorup found that CT scanning provided additional information in 82% of cases, which led to a change in the surgical plan in 64% of operative pilon fractures. Additionally, CT evaluation of fracture displacement and comminution results in high concordance rates among clinicians. Although axial CT images generally provide the most important information for preoperative planning, sagittal and coronal reconstructions are often helpful to clarify the three-dimensional (3-D) configuration of the fracture. Moreover, 3-D CT imaging is now commonplace and can be helpful in completing the evaluation of the fracture.

Key Point

CT imaging is now commonplace and is critical in the evaluation and management of the tibial pilon fracture.

Initial Treatment

Care begins at the scene of the injury with temporary immobilization before transport to prevent further soft tissue damage. On arrival at the emergency department, a thorough history and physical examination should be performed. For polytrauma patients involved in high-energy injury mechanisms, the Advanced Trauma Life Support (ATLS) protocol should be followed. Pilon fractures often have additional injuries, which increases with the severity of the pilon fracture, so a high index of suspicion should always be present. Calcaneus and tibial shaft fractures are the most common concomitant fractures.

Examination of the lower leg and ankle should include a careful evaluation of the soft tissues, paying particular attention to the presence or absence of an open injury and the amount of swelling. A detailed neurovascular examination should also be documented. When the deformity involves posterior and medial displacement of the distal fragment, the deep and superficial peroneal nerves are at risk for injury. Vascular injury is also common. LeBus and Collinge noted arterial abnormalities in 13 of a consecutive group of 25 patients with high-energy pilon fractures screened with CT angiography. Fortunately, all patients had palpable pulses, presumably because of collateral flow, and there were no wound-healing problems after ORIF. However, injury to two or three of the lower limb vessels has been associated with 33% and 100% amputation rates, respectively.

The degree of closed soft tissue damage can be graded according to the system of Tscherne and Oestern, and open fractures are classified according to the system of Gustilo and Anderson. Any deformity should be reduced as soon as possible to prevent further soft tissue compromise and subsequent fracture comminution. Impending open fractures most commonly occur when the distal fragment is displaced posteriorly and the anterior aspect of the distal end of the tibial shaft tents the skin anteriorly. A preliminary reduction should be performed if there is significant deformity, and the fracture should be immobilized in a well-padded splint with the limb moderately elevated. Open fractures should be identified and gross debris removed from the wound in the emergency room, followed by a clean, sterile dressing covering the wound at the time of provisional splinting. Initial radiographs of the ankle and tibia are then obtained to fully characterize the injury pattern (see “ Radiographic Evaluation ” and “Classification”).

Another important consideration in the initial evaluation is the presence of any early signs or symptoms of compartment syndrome. Young males, high-energy injuries, shortening that requires excessive traction to reduce with external fixation, and epidural anesthesia for postoperative pain control are cited risk factors for its development. Sensory changes in the first web space and weakness of toe dorsiflexion suggest a developing anterior compartment syndrome. A deep posterior compartment syndrome is suggested by pain on passive toe dorsiflexion, weakness of toe flexion, and abnormal plantar sensation. A more thorough discussion on the identification and treatment of compartment syndrome can be found in Chapter 17 .

The patient's medical history should be reviewed to identify the presence of any preexisting medical conditions that are associated with poor healing that may require modification of the treatment plan. These include smoking, diabetes mellitus, alcoholism, corticosteroid use, peripheral vascular disease, and osteoporosis.

Key Points

Calcaneus and tibial shaft fractures are the most common concomitant fractures.
Posterior and medial fracture displacement risks injury to the tibial neurovascular bundle.
Anterolateral displacement can injure the deep peroneal neurovascular bundle and superficial peroneal nerve.
Vascular injury is common.
Injury to two or three of the lower limb vessels has been associated with high amputation rates.
Compartment syndrome is common.

Treatment Options

Most surgeons agree that the AO principles of anatomic reduction of the articular surface, restoration of proper alignment, and stable fixation to allow early joint motion are the ideal goals of treatment. However, the ability to achieve these goals is dictated by the severity of the soft tissue and bony injuries and any iatrogenic complications. Fundamental factors influencing treatment include the presence or absence of proximal diaphyseal extension, the amount of displacement or comminution, the inherent quality of the bone, open fracture, soft tissue injury, compartment syndrome, and other factors related to both surgeon and patient.

Closed Treatment

Immobilization with splinting and casting has been used to treat displaced pilon fractures. However, even in the setting of an anatomic reduction, closed treatment of displaced fractures usually fails to maintain alignment of previously displaced fractures, and secondary displacement is common. Current nonoperative methods include closed reduction with immobilization in a short or long leg splint, with later conversion to casting after swelling resolution, and calcaneal traction. These closed treatment methods are generally reserved for fractures in debilitated patients or as a temporary measure to allow for soft tissue healing before definitive surgical management. Most other nonoperative methods have been discarded because some form of operative treatment is usually required. Nondisplaced pilon fractures may do well with either operative or nonoperative treatment. Although it has not been proven that surgical intervention benefits patients with such nondisplaced injuries, we suspect that if fixation can be achieved without undue risk, earlier motion may be of value because prolonged closed treatment immobilization prevents joint motion, which promotes cartilage nutrition and healing. The end result of prolonged immobilization is often joint stiffness and osteodystrophy.

Traction

Skeletal traction of typically 7 to 9 kg (15 to 20 lb) using a calcaneal pin relies on ligamentotaxis to reduce and maintain fracture fragment alignment. It can be useful, especially in the presence of significantly compromised soft tissues. Calcaneal traction is easy to apply, allows ready access to fracture blisters and surrounding soft tissue, and permits some ankle motion while preserving length and relative stability. It is currently used only as a temporization method because it is often unsuccessful in fractures with severe comminution and impaction. Articular fragments that lack capsular attachments will not be reduced with ligamentotaxis, and traction may open gaps in the impacted metaphysis that will not heal without bone grafting (see Fig. 65.26 ).

Surgical Management

Open pilon fractures, patients with compartment syndrome, articular incongruity greater than 2 mm, and malalignment greater than 10 degrees in any plane are operative indications. Clinical outcomes have even been found to be adversely affected when malalignment of greater than 5 degrees is present. The surgeon needs to appreciate that the severity of the soft tissue injury cannot be separated from the degree of skeletal involvement but instead should be combined to create an overall injury pattern. The standard treatment method of pilon surgical management is a staged protocol that allows time for healing of the soft tissues and delayed ORIF. This protocol has evolved significantly over the past 60 years.

Ruëdi and Allgöwer first reported their results of acutely performing ORIF in a large series of patients with pilon fractures. They found good to excellent functional results in 74% of patients after 4.2 years, with 90% of patients returning to their previous occupation. At 9 years, 85% had achieved good to excellent outcomes. However, it is important to emphasize that 75% of these patients had sustained lower-energy, rotational, skiing-type injuries and that only 6% of the fractures were open. Nonetheless, these authors concluded that if a pilon fracture could be reconstructed anatomically and stabilized by rigid internal fixation, a predictably good long-term outcome was possible.

Over the next 20 years, surgeons attempted to apply the same AO principles to higher-energy pilon fractures acutely after injury. It had limited success. In 1986, Ovadia and Beals reviewed 145 pilon fractures. Good to excellent outcomes were obtained in 74% of the 80 patients treated with formal ORIF as compared with 54% of those treated with all other methods. However, when only the severe injuries were evaluated, ORIF yielded good or better results in only 38%. The overall complication rates were significant and included 10 superficial wound infections, 10 cases of osteomyelitis, 5 cases of wound sloughing, 17 cases requiring delayed arthrodesis or arthroplasty, and 3 amputations. Nearly a decade later, many other reports had failed to note any improvements with respect to outcomes and complications. Open treatment of Ruëdi type III injuries by Bourne and associates yielded a disappointing 44% rate of satisfactory results, with a high rate of complications consisting of nonunion in 25%, deep infection in 13%, malunion in 25%, and posttraumatic arthrosis in 63%. McFerran and colleagues reported a 54% rate of complications in severe pilon fractures treated with ORIF, including a 24% rate of wound breakdown and a 17% rate of infection.

Teeny and Wiss noted even more dismal results of ORIF in a series of 60 pilon fractures, with unacceptable clinical outcomes in 75%. Not surprisingly, complication rates increased from 30% in Ruëdi type I and II fractures to 70% in type III fractures, with many patients having more than one complication. These complications included a 37% rate of skin sloughing and a 37% rate of infection in 30 Ruëdi type III fractures as compared with rates of 17% and 0% for lower-energy fractures, respectively. Ruëdi type III fractures were also four times more likely to result in nonunion, seven times more likely to lead to malunion, six times more likely to have problems with unstable fixation and hardware failure, and nearly three times more likely to ultimately require arthrodesis. Rather than correlating infection with the presence of an open fracture, these authors found that it was the presence of wound problems that increased the incidence of deep infection sixfold to 44%. The authors recommended that “if anatomic reduction without soft tissue complications cannot be predicted preoperatively, consideration should be given to alternative types of treatment.” These last words helped guide future treatment protocols toward limited surgical approaches and temporary stabilization of the bone injury until improvement of the surrounding soft tissue before definitive internal fixation.

Because most of the poor results after acute ORIF appeared to be associated with soft tissue complications, many investigators began to utilize more limited surgical approaches, with varying degrees of success. In a prospective study of severe pilon fractures (44% Ruëdi type III, 26% open), Wyrsch and colleagues in the 1990s compared the results of ORIF to bridging external fixation with or without limited internal fixation. Although ankle scores for the two groups were equivalent, complications were more frequent and severe in patients treated with ORIF. However, a significant number of the patients (68%) undergoing ORIF had their definitive stabilization procedure at an average of 3.2 days, when surrounding soft tissues may have been most vulnerable to further injury.

In an effort to improve on the poor results associated with more severe pilon fractures while also avoiding bridging the ankle joint, Tornetta and coworkers proposed an alternative method of treatment. They performed limited internal fixation and hybrid external fixation consisting of semicircular frames with tensioned wires and half-pins in 26 cases and obtained 81% good to excellent results, including 69% good to excellent outcomes, in patients with 13 Ruëdi type III pilon fractures. Complications were fewer and less severe than typical cases treated with ORIF, and early functional results were comparable to those of previous studies but without the related soft tissue complications.

Other investigators have endorsed this concept of limited surgery for severe pilon injuries to avoid the complications associated with formal ORIF. Various techniques have been used, with varying degrees of good to acceptable results, including hybrid fixators, Ilizarov-type or exclusively tensioned wire fixators, ankle-spanning external fixation, and percutaneous screw or plate fixation (see to ).

However, Tornetta's initial success with hybrid fixation was not always reproducible. Bone et al. and Anglen observed that hybrid external fixation with or without limited internal fixation had good outcomes in only 30% to 52% of their patients compared with 79% of patients in the ORIF group. There were also more complications in the hybrid fixation group, including increased rates of overall complications and nonunion. However, these results should be interpreted with caution because hybrid fixation was more often utilized in cases of increased-complexity fracture patterns with a shorter time to definitive fixation. Other studies comparing external fixation versus ORIF have yielded equivocal results.

Although hybrid external fixators are believed to result in less soft tissue complications, they are less stable biomechanically and frequently associated with chronic pain, patient dissatisfaction, and posttraumatic arthrosis in addition to frequent pin tract infections. In an effort to maximize the advantages of ORIF, Watson and colleagues established a staged treatment protocol based on the severity of soft tissue injury. Open fractures and polytrauma patients with pilon fractures were treated with urgent operative stabilization using an ankle-spanning external fixator. Patients with open fractures returned to the operating room an average of 2.5 days later for a second irrigation and débridement procedure and definitive stabilization. Those with closed injuries underwent definitive fracture treatment at an average of 5 days after the initial injury, when the soft tissues had improved. Forty-one patients with Tscherne grade 0 or 1 closed injuries underwent ORIF, whereas 64 patients with grade II and III injuries and all those with open fractures underwent definitive stabilization using a tensioned wire and circular external fixator with or without a limited open approach. At follow-up of almost 5 years, 75% of the ORIF patients and 81% of the external fixation cohort had achieved good to excellent results, with similar results for both groups even when stratified by AO fracture type. Pin-site problems were common in the external fixation group, and the ORIF group had increased complication rates in the AO/OTA 43C group. Although acknowledging that ORIF was still the treatment of choice for AO/OTA 43A and 43B fractures with low-grade soft tissue injury, the authors recommended external fixation for open or closed 43C fractures because of the increased incidence of bony and soft tissue complications. This practice has been echoed by other authors.

Because ORIF allows the best chance of obtaining an anatomic reduction of the articular surface and the state of the soft tissues correlates with the risk of complications, the late 1990s saw the increasing use of staged protocols for the treatment of high-energy pilon fractures. These “span, scan, plan, and definitive fixation” protocol styles combine the advantages of external fixation, delayed treatment, limited surgical exposure, and open reduction, internal and plate fixation of the fracture. In the initial stage, the fibula may be stabilized at the surgeon's discretion and the ankle joint spanned with an external fixator. However, if the patient is likely to follow up with another surgeon, it is generally recommended not to perform initial ORIF of the fibula because this may limit the future surgeon's treatment options. Once the soft tissues have improved, ORIF is undertaken.

Numerous authors since then have reported similarly low rates of complications when performing staged procedures. Boraiah and colleagues treated 59 open pilon fractures with a staged protocol and encountered only two deep infections and three superficial infections. One patient required an amputation after a failed free tissue transfer. Fifty-two patients went on to union, and six required subsequent bone grafting. McCann and coworkers treated 49 pilon fractures (43B and 43C) with staged ORIF at a mean of 13.6 days. They reported a 2% rate of deep infection, a 14% rate of superficial infection, and a 2% rate of wound dehiscence.

Although the use of staged protocols in patients with high-energy soft tissue injuries has undoubtedly reduced the rate of disastrous complications, a dogmatic routine delay before definitive treatment may not be required in all cases. For example, the judicious selection of patients for immediate definitive ORIF has led to good results in a number of studies performed by high-volume, experienced trauma surgeons. Also, certain uncontaminated open fractures will best benefit from primary ORIF and closure at the time of the index procedure. However, caution should be exercised lest we repeat the mistakes of the past, when high-energy pilon fractures did not fare well with definitive fixation in the 2- to 6-day postinjury window. The vast majority of pilon fractures are best treated by delayed definitive fixation after appropriate external fixator stabilization and soft tissue rest.

It should be noted that in rare circumstances, other surgical treatments such as arthrodesis and amputation are performed primarily but are generally regarded as salvage procedures. Primary amputation should be reserved for patients with severe soft tissue and bony injury, particularly if associated with limb ischemia, hypotension, polytrauma, advanced age, or significant neurologic injury (see Fig. 65.27 ). However, loss of plantar sensation is not an indication for amputation. Prior work has shown that a majority of patients will eventually regain their sensation, and therefore plantar sensation loss should not be used as a surrogate for tibial nerve transection.

Once operative management is selected, there are numerous important considerations, including the timing of the procedure(s), surgical approach, and fracture stabilization construct that must be considered. Adherence to established treatment protocols is important because any significant deviation can compromise the clinical outcome and result in irreparable harm and possibly limb amputation. The following sections address these important topics and the evidence behind them.

Key Points

Current nonoperative methods include closed reduction with immobilization in a short or long leg splint, with later conversion to casting.
The end result of prolonged immobilization is often joint stiffness and osteodystrophy.
Most of the poor results after acute ORIF appear to be associated with soft tissue complications.
Open fractures and polytrauma patients with pilon fractures are treated with urgent operative stabilization using an ankle-spanning external fixator.
The “span, scan, plan, and definitive fixation” protocol styles combine the advantages of external fixation, delayed treatment, limited surgical exposure, and open reduction, internal and plate fixation of the fracture.

Timing of Surgery and Staged Protocol Treatment

Timing of Surgery

The timing of surgical intervention is both controversial and critical ( Fig. 65.6 ) because of its influence on wound healing. After an injury, the initial swelling is caused by the fracture hematoma and the effect of shortening and relative instability of the extremity. After 8 to 12 hours, swelling is primarily caused by interstitial edema. This edema is perhaps the single most important factor to control for successful wound healing.

Fig. 65.6, Soft tissue conditions as a function of time after injury. Two surgical “windows” have been proposed—the early period, within 6 hours after injury, and the late period, between 6 and 12 days after injury. However, the risk for complications and, therefore, the timing of surgery remain dependent on an accurate examination and appropriate surgical technique minimizing additional soft tissue injury.

Fracture blisters are common and can occur as early as 6 to 8 hours after injury (see Fig. 65.15C, D, H, and I ; also see Fig. 65.29F and G ). Varela and associates reported an incidence of 29.4% with pilon fractures, which was higher than any other location that they studied. Two types of fracture blisters may develop: those filled with clear fluid and those with bloody fluid. Clear fracture blister fluid represents a partial separation of the epidermis from the dermis, and bloody fluid indicates a complete separation. Giordano and Koval noted that all seven complications in their series of 53 pilon cases involved blood-filled blisters only. They concluded that incisions should not be placed through this type of blister until it has reepithelialized. Marked edema; skin blistering; deep abrasions; and contusions of the skin, subcutaneous fat, and muscle are indicators of significant soft tissue injury. In addition, a broad transitional zone can exist in patients with severe fractures, so the soft tissue injury may extend far from the fracture site. It is important to remember that even when the leg is appropriately elevated and immobilized, progressive soft tissue ischemia usually develops after severe distal lower extremity injuries. Although maximal ischemia can exist as early as 24 hours after the initial injury, it frequently evolves over the initial 2 to 6 days (see Fig. 65.6 ). If a surgical approach through the compromised soft tissues is performed during this high-risk period, a disastrous outcome is all too common. If percutaneous techniques are applicable, the timing of surgery can be more flexible.

More recently, there has been interest in the use of lymphedema wrapping techniques to improve soft tissue swelling and allow earlier operative treatment. Whatley et al. found that using lymphedema treatments in patients with pilon fractures after initial ankle-spanning external fixation reduced the time to definitive open treatment by approximately half compared with standard techniques (11 vs. 20 days, respectively). However, the exact role of lymphedema treatments in improving the treatment of patients with pilon fractures is not yet known.

Soft Tissue Management

In general, operative intervention should be deferred until the soft tissues have healed and the swelling has begun to subside. This usually requires a period of 7 to 14 days, with most staged studies quoting 10 to 14 days as their average time until definitive treatment. Resolution is heralded by the absence of shiny-appearing skin and a positive “wrinkle sign” over the planned approach locations. Delaying surgery beyond 3 weeks makes the operation more technically difficult and reduces the probability of achieving an anatomic reduction. This is due to the progressive formation of callus and development of disuse osteoporosis and subsequent bone resorption at the fracture site. Prolonged immobilization may also jeopardize the viability of articular cartilage.

Due to the considerable risk of soft tissue complications when performing formal surgical approaches in the acute period, (see Figs. 65.8, 65.10, 65.13, 65.15, 65.16, 65.18, 65.20, 65.29, and 65.31 ) an initial skeletal stabilizing procedure is typically performed within 24 hours of injury. This initial surgery commonly includes irrigation and débridement of open wounds, closed fracture reduction with application of an ankle-spanning external fixator, and closure of any traumatic wounds.

Although many configurations are possible for an ankle-spanning external fixator, the simplest construct is achieved with two tibial half-pins, typically 5 mm in diameter, and a 5-mm transfixion pin through the tuberosity of the calcaneus (see Figs. 65.11C and D, 65.15F–I, 65.20G and H, and 65.22A ). The tibial pins are ideally placed proximal or well away from potential future ankle incisions for definitive fixation. For significantly unstable fracture patterns or if a significant delay to definitive treatment is anticipated, then smaller-diameter pins can be added to the first and/or fifth metatarsal to prevent prolonged ankle plantarflexion (see Figs. 65.15F–I, 65.16I and J, 65.20E and F, 65.22, and 65.31G–J ; also see “ Joint-Spanning Frames ”). Alternatively, a postoperative shoe can be secured to the external fixator frame using an Ace bandage to prevent equinus contracture at considerably reduced expense. After the initial procedure, the patient is discharged home and then reexamined at weekly intervals. Once the edema has resolved, the patient returns to the operating room for the second stage of the procedure. The theoretical advantages of such a protocol include providing skeletal stabilization to maximize soft tissue recovery and reducing the length of hospitalization, associated costs, and exposure to nosocomial pathogens.

Staged Protocols

Staged surgical treatment is currently the preferred technique for most pilon fractures. One of the earliest studies advocating for this approach was by Sirkin and associates. They treated 56 patients with immediate open reduction and plate fixation of the fibula when fractured and application of an ankle-spanning external fixator (see Figs. 65.8, 65.10, 65.11, 65.15, 65.16, 65.18, and 65.20 ). Definitive fixation was then performed on average 13 days later. Thirty-four patients had closed fractures, and 22 had open injuries (3 type I, 6 type II, 8 type IIIA, 5 type IIIB). There were no cases of wound dehiscence or full-thickness necrosis requiring secondary soft tissue coverage. Osteomyelitis developed in one patient with a closed fracture and in two with open fractures. One of these injuries resulted in an amputation.

Using a similar protocol, but with intramedullary stabilization of the fibula, Patterson and Cole treated 22 consecutive AO/OTA type C3 pilon fractures. Definitive stabilization of the tibia was performed an average of 24 days after injury. They obtained 77% good, 14% fair, and 9% poor results, with all but one fracture healing at an average of 4.2 months. No infections or soft tissue complications developed. At follow-up, two patients required tibiotalar arthrodesis.

Blauth and colleagues retrospectively separated 51 patients (4 AO/OTA type B, 2 type C1, 26 type C2, 19 type C3) into three different treatment groups. Fifteen patients underwent acute ORIF, whereas the other two groups were treated with initial limited ORIF of the articular surface followed by either definitive external fixation of the ankle or temporary external fixation and delayed ORIF. Overall, 80% of patients returned to work, 86% resumed their previous sporting activities at the same or a reduced level, and 92% were satisfied with their results. Infection requiring surgical débridement occurred in 13 patients (25%), with a trend toward a greater risk of infection noted in the acute ORIF group (33%) versus the staged and limited ORIF treatment groups (12.5%). Although this difference was not statistically significant, it is important to consider that all the patients in the acute ORIF group had lower-energy, closed injuries. In the group undergoing single-stage minimal osteosynthesis and external fixation, poorer outcomes were attributed to the long period of immobilization needed.

Although staged pilon fracture treatment has been shown to be beneficial in most patients, there is still debate about the timing of fibular fixation and whether it is necessary in all cases. In many of the early studies using staged protocols, it was typically recommended that the fibular fracture be surgically stabilized during the first stage to minimize any further insult to the soft tissues. However, many authors have challenged the recommendations to acutely reduce and fix associated fibular fractures. If the surgeon performing the initial procedure is not planning to definitively fix the fracture, then it is generally recommended they not stabilize the fibula acutely. This helps the definitively treating surgeon because the full spectrum of surgical approaches is still available, and the surgeon is not limited by a previously made lateral incision and implants (see Fig. 65.11 ). An additional discussion on the potential advantages and disadvantages of fibular stabilization is provided in “Fibular Fixation” within the “Restoration of Length” section.

Another adjunct to staged protocols is early small fragment fixation of the metadiaphysis or select portions of the articular surface. This technique can aid the surgeon by “downgrading” the severity of a complete articular fracture pattern to a partial articular pattern. Dunbar and coworkers treated nine AO/OTA type 43C fractures, which had an oblique proximal extension of the fracture into the diaphysis. The diaphyseal fracture line was stabilized with a small fragment plate placed in an antiglide fashion through a limited proximal incision at the time of initial treatment. Given that this diaphyseal fragment retained its attachment to a portion of the articular surface, an indirect reduction and stabilization of a portion of the plafond was achieved without violating the tenuous soft tissues about the ankle (see Fig. 65.21 and Fig. 65.29 ). No infections, wound complications, or nonunions were encountered in this small series.

Ketz and Sanders treated nine patients with type 43C fractures with a staged approach consisting of acute posterior plafond ORIF via a posterolateral approach and placement of a spanning fixator (see Figs. 65.13 and 65.29 ). Seven patients also had ORIF of their fibular fractures through the same approach. Patients then returned to the operating room at an average of 18.5 days later for definitive treatment of the remaining pilon fracture through a direct anterior approach. Only one deep infection occurred, and there were better articular reductions and outcomes compared with patients treated by delayed anteromedial approach alone. This included a 0% rate of articular incongruity of the posterior articular surface versus a 40% rate of more than 2-mm incongruity in the former. At follow-up, only 33% of the patients treated by the staged posterior and anterior approaches had radiographic evidence of arthritis versus 70% in those treated with an isolated anteromedial approach. American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot scores were also superior (86.4 and 85.2 vs. 69.4 and 76.4). In contrast, Chan et al. recently reported their results of type 43C pilon fractures treated in a similar staged manner of acute posterior plafond stabilization through a posterolateral approach and delayed anterior fixation compared with a group treated exclusively via a delayed anterior approach. They found that the two-approach group had a significantly higher rate of nonunion (40% vs. 19%) and no significant difference in articular malreduction of more than 2 mm (6% vs. 17%). Although no definitive recommendation can be made regarding acute fixation of the posterior plafond, surgeons must balance the added surgical dissection with the potential for improved articular reduction.

Finally, as already mentioned, the judicious selection of appropriate patients and expert surgical technique can produce good results with a low rate of complications should the surgeon elect to perform early definitive treatment within the first 24 hours after injury. White and associates reported on a retrospective review of 95 patients with AO type 43C pilon fractures treated with early ORIF by experienced trauma surgeons. The median time to surgery was only 18 hours, with 71% of the patients operated on within 24 hours. During this time period, 20 patients with type 43C pilon were unable to be treated with early ORIF due to soft tissue injury, systemic factors, previous external fixation at another institution, or delayed transfer. Wound dehiscence or a deep infection requiring reoperation occurred in only 6% of patients. Six patients (6%) had delayed fracture healing or nonunion. Along with economic benefits, the clear benefit of single-stage early definitive care is the greater ease of obtaining an anatomic reduction in a fresh fracture. However, this tactic of early definitive treatment must always be measured against the risks of possible disastrous soft tissue complications.

Key Points

Initial surgery commonly includes irrigation and débridement of open wounds, closed fracture reduction with application of an ankle-spanning external fixator (with or without anatomic fibula fixation), and closure of any traumatic wounds.
Early small fragment fixation of the metadiaphysis or select portions of the articular surface effects a “downgrading” of the severity of a complete articular fracture pattern to a partial articular pattern.
Once the edema has resolved, the patient returns to the operating room for the definitive osteosynthesis.
Along with economic benefits, the clear benefit of single-stage early definitive care is the greater ease of obtaining an anatomic reduction in a fresh fracture.
The tactic of early definitive treatment must always be measured against the risks of possible disastrous soft tissue complications.

Surgical Approaches

The classic two-incision AO approach is an anteromedial incision to expose the tibia and a posterolateral incision for the fibula. However, in response to modern biologic trends, including more minimally invasive strategies, alternative surgical exposures have evolved to address the many varied pilon fracture patterns. These often involve more than one incision. Because no one approach provides an optimal surgical exposure of all fracture patterns, the surgeon needs to be familiar with a number of options to achieve the best outcomes. Regardless of the specific exposure(s) at the time of surgery, the soft tissues must be respected, which begins with an adequate anterior soft tissue bridge between incisions. For the classic anteromedial and posterolateral incisions ( Figs. 65.7 and 65.8 ), some investigators have recommended a skin bridge as large as 12 cm, although a minimum of 7 cm has historically been advised to prevent wound-healing complications. However, more recent evidence questions such limits because a number of studies have shown that skin bridges as narrow as 5 cm have a low risk of complications. In a prospective study from 2008, Howard et al. found that the classically taught 7-cm skin bridge between incisions can be violated when the soft tissues and lower leg angiosomes are respected. Multiple incisions were used to treat 46 fractures, including 39 anterolateral, 8 anteromedial, 11 medial, 4 posteromedial, and 44 posterolateral. Only a minority of patients had skin bridges greater than 7 cm, whereas most patients had 5 to 5.9 cm between incisions, with soft tissue complications occurring in only 9% of patients.

Fig. 65.7, Classical anteromedial skin incision. A minimum of a 7-cm skin bridge has been historically recommended between the medial and lateral skin incisions to avoid flap devascularization and necrosis.

$Fig. 65.8, A 25-year-old man was involved in a rollover motor vehicle accident and sustained polytrauma, including an AO type C2 pilon fracture with diaphyseal extension and Tscherne type II soft tissue injury. (A and B) Plain radiograph and axial computed tomography (CT) imaging delineate the nature of the fracture. (C and D) On the day of injury, length and alignment were achieved through ligamentotaxis with a temporary spanning external fixator and plate fixation of the fibula. Significant swelling at the time of temporary fixation precluded definitive surgery. (E and F) Open reduction and internal fixation (ORIF) through an anteromedial approach with a nonlocking anterolateral plate 11 days later. A percutaneously placed lag screw with a washer was used to stabilize the Chaput fragment. Because of the simple nature of the articular injury, a more limited arthrotomy and bridge-plating technique also would have been acceptable options. (G–K) Radiographic and clinical appearance at 1-year follow-up with a pain-free bony union and good range of motion, with only slight loss of dorsiflexion. He returned to full work as a laborer.$

Although these studies do not imply that extensile incisions can be made in parallel with impunity about the ankle, they do suggest that with careful planning, the surgeon is not limited to the classic two-incision approach at all times. It is also important to note that the ability to successfully use smaller skin bridges in the presence of multiple incisions is based on using shorter (generally 2 to 4 cm in length) “minimally invasive” incisions (see Figs. 65.9, 65.10, and 65.13 ) and respecting the status of the soft tissues. Another option is to use “no-touch” techniques with appropriately placed Kirschner wires (K-wires) to assist in visualization and lessen the need for the use of self-retractors, which might exert undue tension on the flaps. Regardless of whether one extensile or multiple smaller incisions are used, it is important for the surgeon to be comfortable with all exposures so that each fracture pattern can be approached to optimize reduction and stabilization.

Anteromedial Exposure

The anteromedial exposure of the tibia is the classic and most commonly used surgical approach for tibial pilon fractures. The patient is positioned supine with a foam ramp under the operative extremity. A thigh tourniquet is used but inflated only if bleeding interferes with visualization. The skin incision (see Figs. 65.7 and 65.8E and F ) begins proximally, 5 to 10 mm lateral to the anterior tibial crest. It is extended distally to the ankle joint crossing over the tibialis anterior muscle and then acutely angled toward the medial malleolus. Increasingly popular is a straighter and more extensile modified skin incision that follows the medial border of the tibialis anterior tendon distally toward the talonavicular joint. A branch of the superficial peroneal nerve is unlikely to be encountered through this extensile incision, although if present, it would cross the distal aspect of the incision at the level of the superficial fascia.

Regardless of the particular skin incision, the medial border of the tibialis anterior is exposed, and a transretinacular incision is made straight to the tibia, creating full-thickness tissue flaps. The sheath of the tibialis anterior tendon should not be violated because this structure, unlike the tendon itself, will accept a skin graft should soft tissue problems arise. Additionally, the tissue flaps should be retracted with minimal trauma to the skin edges throughout the remainder of the case. The anterior compartment tendons and neurovascular bundle are mobilized and retracted laterally, offering exposure of the anterior distal tibia. Visualization and treatment of laterally based fractures through this window can be challenging, highlighting some of the limitations of the anteromedial exposure.

A long incision (see Figs. 65.8E and F ) is not always required for exposure, reduction, and stabilization of the articular surface. A limited open approach with mini-arthrotomy is most appropriate for minimally displaced or nondisplaced fractures ( Fig. 65.9 ) and fractures with major fragments that are reduced indirectly after the application of traction (see Fig. 65.20 ). A limited approach can also be useful for complex fractures (e.g., segmental fractures, or those with severe metaphyseal-diaphyseal comminution) treated with independent articular screws and minimally invasive bridge plating ( Fig. 65.10 ) or external fixation techniques (see Fig. 65.23 ).

$Fig. 65.9, A 56-year-old woman fell from standing height, sustaining this AO type C1 pilon fracture with a Gustilo grade 2 open wound. (A–C) Anterior-posterior (AP), mortise, and lateral radiographs. Note the minimally displaced long spiral fracture extending toward the joint. (D and E) Computed tomography (CT) scan delineating the articular component. (F) Clinical picture after urgent irrigation, débridement, and exploration of the open wound. (G) A limited separate exposure of the articular surface allowed its anatomic open reduction and (H) percutaneous insertion of a precontoured, low-profile plate (minimally invasive plate osteosynthesis [MIPO]), using lag screws for the joint and locking screws to stabilize the diaphyseal segment. (I and J) Postoperative AP and lateral radiographs showing anatomic reduction and alignment.$

$Fig. 65.10, This 45-year-old woman was the restrained driver of a car struck head-on. She sustained an AO type C2 fracture with metaphyseal-diaphyseal extension, severe metaphyseal comminution, and Tscherne type II closed soft tissue wound. (A and B) Anterior-posterior (AP) and lateral plain radiographs demonstrate the displaced fracture. (C) On the day of injury, a temporary spanning external fixator was applied, attached distally to a calcaneal transfixation pin. Length and alignment were restored by application of traction across the ankle (ligamentotaxis). (D and E) A computed tomography (CT) scan was obtained to better evaluate the articular fracture pattern and metaphyseal comminution. (F and G) After resolution of significant soft tissue edema, open reduction and internal fixation was performed 12 days postinjury with the use of a small arthrotomy to reduce the articular surface. After the lag screw fixation of the articular surface, a precontoured, low-profile percutaneous plate (minimally invasive plate osteosynthesis [MIPO]) was used to stabilize the metadiaphysis. (H) Clinical picture on postoperative day 19.$

Direct Anterior Exposure

The direct anterior approach can offer access to both the anteromedial and anterolateral fragments and is the favored alternative approach of some surgeons. A straight incision is centered over the tibiotalar joint. The medial superficial peroneal nerve branches should be protected if seen and retracted. The extensor retinaculum is incised lateral to the tibialis anterior tendon, taking care not to violate its tendon sheath. At this point, it is important to appreciate the relationship of the major structures deep to the retinaculum at the level of the ankle joint from medial to lateral: tibialis anterior, extensor hallucis longus, neurovascular bundle, and extensor digitorum longus. The deeper interval is typically created between the tibialis anterior and extensor hallucis longus. Traditionally used for ankle arthrodesis or total ankle arthroplasty, this approach can be quite useful for certain pilon fractures. However, McCann and colleagues, who recommended this as their “preferred method,” still used it in only 12 of their 49 pilon cases (7 were anterolateral, 11 anteromedial, 5 posteromedial, 8 medial, and 6 posterolateral).

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here