Emergency Care of Musculoskeletal Injuries

Fracture Types

A fracture is a disruption of the normal architecture of bone. Fractures can be acute, subacute, or chronic. Subacute and chronic fractures, while frequently needing treatment, can often be managed on an ambulatory basis and do not require emergent care. Radiographically, acute fractures can be differentiated from older fractures by the identification of sharp, well-defined edges of the fragments. Older fractures will have evidence of callus formation and a blunting of the fracture edges. Chronic fractures can be radiographically dramatic because of bony hypertrophy and/or adjacent structure destruction. A simple history from the patient usually determines that these do not require emergent management ( Fig. 19.1 ).

Because of increased plasticity, a more substantial periosteum, and the presence of growth plates, children’s bones are at risk for a different set of fractures ( Fig. 19.2 ). Plastic deformity of a long bone in a pediatric patient is deformation of the bone without actual disruption of the bone cortex. Radiography of the contralateral extremity can aid in diagnosis. Diagnosis of the deformity often necessitates radiography of the contralateral extremity to confirm asymmetry. Axial loads of long bones in children can lead to buckling of the cortex without a visible fracture line, appropriately termed a buckle fracture. Incomplete disruptions of the cortex are termed greenstick fractures in children or infractions in adults. A greenstick fracture consists of a cortical disruption on one side of the bone, with a buckle fracture or plastic deformation on the opposite side. The dense periosteal layer in children can contribute stability to many of these fractures if the layer remains intact. In some cases, radiographs will be normal, yet the child will not use the extremity. Care must be taken to ensure that there is no missed partial or complete fracture through the cartilaginous growth plate (physis). Physeal fractures are described by the Salter-Harris classification ( Fig. 19.3A ). These centers of bony growth around the ends of each bone ossify at different points in a child’s life. Disruption of one of these “ossification centers” can alter the future growth of the affected bone, leading to length discrepancies or angular deformities. A high level of clinical suspicion is necessary to diagnose these injuries.

When a bone fails through an area weakened by preexisting disease, it is termed a pathologic fracture. Causes may include weakness from primary bone tumors, metastatic lesions, infection, metabolic disease, and injury to an old fracture site. Although they are not commonly referred to in this way, fractures in osteoporotic bone are technically pathologic. However, the term insufficiency or fragility fracture is most frequently used to describe these injuries. In contradistinction to acute fractures in healthy bone, fragility fractures normally result from accidents with much lower energy, such as a fall from standing height. Hip fractures, compression fractures of the vertebral bodies, and distal radius fractures in older adults are common examples.

A fracture is considered open when an overlying wound produces communication between the fracture site and the outside environment. This is a very important determination that has ramifications for the immediate treatment, the definitive treatment, and the long-term outcomes. Open fractures can range from small poke-holes to severe soft tissue degloving. The Gustilo classification is typically used to grade the degree of soft tissue; but in practice, the authors have found that this can be simplified to high energy and low energy , leading to a more consistent determination of treatment. High-energy fracture patterns indicate that the soft tissues as well as the bones have absorbed large forces. Although the skin laceration is the most obvious component, the energy of the fracture, degree of contamination, and soft tissue injury must all be taken into account in grading the severity of the injury. Final grading of open fractures occurs in the operating room, after thorough debridement and evaluation of the soft tissue envelope. Contamination of bone can lead to the development of osteomyelitis and all its catastrophic consequences and thus necessitates emergency treatment.

A fracture that extends into a joint is termed intraarticular. These injuries are normally caused by an axial load across the joint. The joint surface must be perfectly smooth in order to function correctly, so displaced intraarticular fractures require anatomic reduction and rigid fixation to minimize the risk of posttraumatic arthritis. This is distinctly different from a fracture of the diaphysis (shaft) of a long bone. A shaft fracture must only be held in good alignment and at the appropriate length. If the bone heals imperfectly in appearance but is mechanically sound, then the end goal is achieved. Articular fractures must not only be in sound mechanical alignment but also must be perfectly reduced in order to achieve the best possible long-term outcome. In some instances, there is enough cartilage damage from the injury itself that posttraumatic arthritis is unavoidable.

Long bone fractures are characterized by the anatomic location of the fracture ( Fig. 19.3B ). The epiphysis includes the area between the physis, or physeal scar, and articular surface. The metaphysis is located between the epiphysis and shaft and includes the growth plate. The diaphysis encompasses the shaft of the bone between the proximal and distal metaphysis. The diaphysis is made up of mostly dense cortical bone, which has less vascularity than the soft cancellous bone of the metaphysis. This difference in vascularity affects the rate at which the bone heals. Fractures can be described according to location within these three sections or according to the location in the bone—proximal, middle, and distal. Often, these fractures occur around muscular attachments to the bone, thus affecting how the fracture is displaced and how the reduction of the fracture will be achieved.

Metaphyseal fractures of the distal humerus and femur are referred to as supracondylar or intracondylar in reference to the adjacent epicondyles, the medial and lateral bony prominences to which the stabilizing ligaments and muscles of the elbow and knee are attached. The articular surfaces distal to the epicondyles are known as condyles. Intracondylar fractures are intraarticular and may extend proximally. Such distinctions are important because they can drive the decision for type of definitive treatment as well as the intraoperative surgical plan.

After describing the location of a fracture, the actual fracture pattern should be described ( Fig. 19.4 ). The orientation of the primary fracture line may be transverse, oblique, or spiral. Bones are weakest in torsion, and spiral fractures result from torsional forces. Transverse and oblique fractures result from directly applied forces where the bone is “bent” over an object or fails under off-axis loading. Often, there is a combination of these various forces. Local comminution can occur in the form of wedge or “butterfly” fragment. When a bending moment is applied to a bone, there is a resultant compressive force on the bone on the concave side of the bend and a reciprocal tension on the convex side. Bone initially fails on tension side, and as the fracture propagates toward the concave side, the fracture will move around the compressed bone both proximal and distal to it, creating a wedge-shaped fragment, or butterfly. Comminution refers to the presence of multiple fragments within an individual fracture site and usually indicates a higher energy injury or weakened bone in an older patient. Segmental fractures occur at multiple levels in the same bone.

Displacement, if present, is described from a combination of principles. These deformities may occur in any plane. When viewed on plain radiographs, all injuries will be resolved into pure coronal or sagittal displacement. However, the true displacement usually occurs in a plane that is somewhere in between. Translation, angulation, rotation, and shortening are all components of fracture displacement. Translation is the relationship of the proximal fracture fragment to the distal one. It is described in terms of percentage of overlap. A fracture with 100% translation in any plane is completely displaced. Angulation is simply the angle created by the displaced fracture fragments. It is conventionally described in two ways. The first is by the direction of displacement of the distal fragment, and the second is by the direction of the apex of the fracture. For example, the fracture shown in Fig. 19.5 may be described as dorsally angulated or apex volar angulated. The final component is rotation. To describe rotation exactly, a full-length film of the limb segment involved, including the joints above and below, must be examined. Alternatively, rotational deformity may be assessed clinically by comparing the injured limb with the contralateral side.

Once a fracture has been identified, it must be described in a consistent, systematic manner. All descriptions begin with whether the fracture is open or closed. The amount of soft tissue involvement is described. A closed fracture is assumed if, after careful evaluation, there is no observed communication between the fracture and outside world. The presence of an intraarticular fracture is then communicated. The side of the body and injured bone are stated next. A description of the pattern, followed by its location in the bone, is indicated. The displacement of the fracture fragments is related. Finally, it is important to indicate any associated, nonorthopedic injuries that may alter the timing and type of initial orthopedic management. Adherence to this scheme allows complete understanding of the fracture.

Other Injuries

Ligamentous injuries are commonly encountered in association with traumatic injuries to bones and joints. When a ligament is damaged but is still in continuity, it is termed a sprain. Sprains can range in severity from minor injuries to significant instability about a joint. Grade I ligamentous injuries are caused by stretching of a ligament or ligament complex. They do not normally result in instability. A simple ankle sprain is a typical example of this type of injury. Partial ruptures of ligaments can result in minor instability and are considered Grade II injuries. Complete ruptures, or Grade III injuries, lead to significant instability at the associated joint. Avulsion fractures at the insertion of ligamentous structures also fall into this category. Ligamentous injuries cannot be overlooked because they can produce significant joint instability and endanger the surrounding soft tissue and neurovascular structures. This detail is critical in evaluating musculoskeletal injuries. A full neurovascular examination should be performed whenever there is suspicion of joint instability. Although most ligamentous injuries do not require urgent orthopedic management, stabilization or immobilization of the joint with a splint or brace is usually advisable.

A strain is an injury to a muscle or tendon. These injuries are most commonly of an overuse nature. Further loading of the already weakened structure can compound these injuries and lead to muscle or tendon rupture. Rest, ice, compression, and elevation are the mainstays of treatment for a strain; however, more urgent orthopedic management is necessary for a rupture. Although many tendon ruptures can be treated nonoperatively, proper positioning of the joint is important to ensure that the tendon scars down in a functional position. If operative management is pursued, it should occur fairly urgently. Scarring of the tendon tract and contracture of the muscle significantly complicate the operative procedure.

Joint injury without fracture is common in axial load injuries. Articular contusions, or bone bruises, usually heal with a period of rest and restricted weight bearing but can lead to late degenerative changes in the joint. A more significant osteochondral defect occurs when a piece of articular cartilage, along with its underlying subchondral bone, is separated from the surrounding joint surface. Small osteochondral defects can be asymptomatic; however, many of these lesions can lead to chronic pain and joint degeneration. In some cases, the osteochondral fragment is large enough to be seen on plain radiographs. In these cases, it is important to immobilize the joint to minimize joint damage from the free-floating bone fragment. Other commonly injured joints are the intervertebral discs in the spine. These discs are made up of a viscoelastic nucleus pulposus surrounded by a dense, fibrous anulus fibrosus. With a great enough axial load, the nucleus pulposus can herniate through the anulus, resulting in a disc herniation. This disc bulge can impinge on nerve roots, causing back and radicular pain. Disc herniations rarely need surgical intervention and often resolve with a course of physical therapy. Very rarely, severe disc bulge in the lumbar spine can cause significant impingement on the cauda equina, resulting in cauda equina syndrome. This is a surgical emergency and is discussed in more detail later in the chapter.

History

Obtaining a detailed history of a skeletally injured patient is essential for accurate diagnosis and treatment. This can be challenging with multiply injured and older patients in the trauma setting; however, it is important to gather as much information as possible about the mechanism of injury. Often, trauma patients are unable to give accurate histories because of unconsciousness, intoxication, dementia, or delirium. In these cases, an account of the mechanism of injury and patient history should be obtained from family members, emergency medical response crew members, or other witnesses to the accident. Descriptions from the injury scene can be helpful because common patterns of injury follow from specific mechanisms ( Table 19.3 ).

A general history that includes demographic information, past medical history, past surgical history, and social history is obtained. Knowledge of allergies, current medications, and time since last oral intake is useful in guiding treatment. One should adhere to the normal ED protocol of not allowing food or drink while under assessment. Information about the position of the limb before and after the injury as well as the direction of the deforming force can help predict the resulting injuries. Ambulatory status before the injury helps determine realistic goals for functional recovery, and it can also drive treatment decisions, in particular, knowing if a patient ambulates in the community or primarily only within his/her household. Any transient neurologic symptoms, such as loss of consciousness, numbness, dysesthesias, and spasm, must be documented. Loss of bowel or bladder control in patients with back or neck pain must also be noted. The time elapsed since injury becomes critical information in a patient with a vascular injury, open wound, or dislocation.

Trauma Room Evaluation

Examination of a multiply injured patient must first follow advanced trauma life support (ATLS) protocols in a systematic fashion and must be accompanied by appropriate treatment. The concept of life before limb demands that the ABCs ( a irway, b reathing, and c irculation) be addressed before evaluating for any orthopedic injuries. Hemodynamically unstable patients are assumed to be in hemorrhagic shock until proven otherwise. A search for the source of hemorrhage is undertaken and may include examination of the pleural cavities, abdomen, extremities, retroperitoneum, and pelvis. A plain chest radiograph may quickly reveal a hemothorax. Chest tubes are placed if necessary.

Pelvic instability and the need for rapid external pelvic fixation are addressed. A single examination of the pelvis for instability, performed by an experienced examiner, can be undertaken. There is debate about whether the anteroposterior (AP) pelvic film, which has traditionally been considered part of the standard trauma radiographic series, is justified with the advent of newer, ultrafast computed tomography (CT) scanners. Paydar and associates found that in hemodynamically stable blunt trauma patients with normal findings on physical examination, 99.7% of pelvic radiographs were negative. Should a pelvic fracture be suspected, plain radiography initially can be done not just for injury characterization but also as a baseline for follow-up examinations. Intraperitoneal hemorrhage can be evaluated by a focused assessment with sonography in trauma (FAST) examination, diagnostic peritoneal lavage, or CT scan. Pelvic fracture patients require special consideration in the use of these tests. FAST scanning has been shown to lack sensitivity in detecting intraperitoneal bleeding in patients with a pelvic fracture. Diagnostic peritoneal lavage has increased sensitivity; however, false-positives in patients with pelvic fractures can occur. The current recommendation for hemodynamically stable patients with a pelvic fracture is to undergo CT of the abdomen and pelvis with intravenous (IV) administration of a contrast agent to evaluate for intraperitoneal bleeding, regardless of FAST results.

The patient’s neurologic status is noted on admission, and the Glasgow Coma Scale score is calculated. Patients with suspected head injury need to be evaluated as soon as possible by CT. Peripheral vascular injuries and musculoskeletal injuries are next in priority, followed by maxillofacial injuries.

In the initial care of musculoskeletal injuries, open fractures or those with vascular injury or compromise, such as compartment syndrome, take precedence. Although the previous dictum of addressing open fractures in the operating room within 6 hours of injury may no longer hold true, open fractures still require relatively urgent operative care. More important, emergent trauma room management, including administration of appropriate antibiotics, tetanus prophylaxis, gross debridement, copious irrigation, splinting, and wound coverage, is imperative for preventing future infection. Sterile dressings placed in the trauma room need to be left in place until the patient reaches the operating room. This practice has led to decreased infection rates compared with routine redressing of wounds in the trauma area.

Unstable pelvic fractures are addressed in the primary survey because of the possibility of exsanguination. Traumatic spine injuries with associated neurologic compromise also deserve immediate attention. These exceptions aside, examination and management of the extremities are deferred to the secondary survey after the airway has been controlled and hemodynamic stability has been obtained. In a team approach, these examinations and treatments take place simultaneously. One caveat to this protocol is the conscious patient who is able to follow commands but will need intubation to protect the airway. In this case, a cursory neurologic examination of the extremities should be performed before sedation or intubation. Documentation of motor and sensory function in the upper and lower extremities is valuable information and takes only seconds to carry out. Throughout the resuscitation phase and during the remainder of the hospital course, reexamination in the form of the tertiary survey will ensure that no injury goes unrecognized.

Evidence of pelvic fractures is assessed early in the resuscitative effort. Massive flank or buttock contusions and swelling are indicative of significant bleeding. The Morel-Lavallée lesion is an ecchymotic lesion over the greater trochanter that represents a subcutaneous degloving injury. This lesion is frequently associated with acetabular fractures. Blood at the urethral meatus, signifying injury to the genitourinary tract, may be a sign of an underlying pelvic fracture. Palpation of the symphysis pubis and the sacroiliac joints can help determine the presence of disruption of these joints. Gentle rocking and lateral compression (LC) through the anterior iliac crests can provide helpful clues to the stability of the pelvic ring. Any opening or looseness signifies instability and may represent a source of hemorrhage. Rectal and vaginal examinations are performed, noting the presence of gross blood, lacerations, bone fragments, hematomas, or masses. Wounds and palpable bone fragments found on either of these examinations are diagnostic of an open pelvic fracture, which carries a poor prognosis. Rectal examination can also reveal a high-riding prostate gland, another indication of injury to the genitourinary tract.

The trauma team must always take steps to protect the patient from self-inflicted or iatrogenic spinal cord injury. Therefore, full spine precautions must be observed until it is confirmed that the patient’s vertebral column is intact, either by physical examination and clinical findings or by radiologic confirmation, when warranted. Fitting the patient with a hard, cervical collar stabilizes the cervical spine. Maintaining the patient in a supine flat position at all times protects the thoracic, lumbar, and sacral segments of the spine. If the patient is to be moved, a strict log roll technique is used. At times, a patient may have to be physically restrained to prevent potential self-inflicted injury by head or lower extremity movements that could impart rotational, translational, or bending moments to the vertebral column. Special care must be taken with combative patients or those with altered mental status who may have lost the ability to protect themselves from further injury. On examination of the back, the examiner notes the presence of deformity, edema, or ecchymosis. Tenderness elicited on palpation of the spine is recorded for each level at which the patient complains of pain. Distinction is made regarding whether the pain is midline or paraspinal. Perianal sensation and rectal sphincter tone should be evaluated to test sacral nerve root function. Deep tendon reflexes and pathologic reflexes, such as the bulbocavernosus and Babinski reflexes, are tested.

Plain radiographs of the cervical spine, including AP, lateral, and open-mouth odontoid views, were previously considered part of the standard trauma series of radiographs. Recently, however, Mathen and associates have shown that the standard plain films fail to identify 55.5% of clinically relevant fractures identified by multislice CT and add no clinically relevant data. Similarly, CT of the thoracic, lumbar, and sacral spine is faster and more accurate than radiography at identifying traumatic injury. With most trauma patients undergoing CT of the chest, abdomen, and pelvis, reformatting of the data into spinal reconstructions adds neither time nor radiation exposure. With these data, plain films are no longer indicated.

Examination of the extremities in either a patient with isolated injuries or a polytrauma patient follows a simple, systematic, and reproducible pattern. Even when an isolated extremity injury is the primary reason for evaluation, the entire skeleton must be examined. The examiner must not be distracted from the task by obvious or severe injuries. Deformity, edema, ecchymosis, crepitus, tenderness, and pain with motion are the cardinal signs of an acute fracture. Each limb segment needs to be examined for lacerations and the signs of trauma described earlier. All joints are put through passive range of motion, at a minimum. Active range of motion is tested whenever possible. Joint effusions are evidence of intraarticular disease (e.g., ligament or cartilage damage or an intraarticular fracture). The joints are then manually stressed to assess the integrity of the ligamentous structures. A neurovascular examination is performed and documented. Pulses are recorded and compared with the opposite uninvolved extremity when possible. Doppler signals are obtained when palpable pulses are not present or are weak. Measuring the ankle-brachial index (ABI) is important when vascular injury is suspected. Motor function and sensation must be documented for the extremity dermatomes as well as for the trunk in a patient with thoracic spine pain. To avoid the complications of a missed compartment syndrome, palpation of the involved compartments is performed. Any firm or tense compartments are checked for increased pressure if time and the patient’s condition allow. Fasciotomies are performed urgently if pressures are elevated. Gross alignment and interim immobilization of long bone fractures are achieved before transportation of the patient from the trauma room. This helps prevent further damage to underlying soft tissues, reduces the patient’s discomfort, facilitates transportation, and may help prevent further embolization of intramedullary (IM) contents. Traction splints or skeletal traction is applied when indicated.

Diagnostic Imaging

Radiographic examination is used to supplement and to enhance the information gathered during the primary survey, history, and physical examination. In a multiply injured patient, the ATLS protocol calls for a lateral cervical spine film and AP views of the pelvis and chest. However, as noted earlier for a stable, conscious patient with no physical examination findings of pelvic trauma, the pelvic film may be deferred for the pelvic CT scan. Cervical spine radiographs should be deferred for a CT scan of the cervical spine (if available). The secondary survey then dictates which extremity radiographs are necessary.

In filming long bone injuries, it is important to verify the integrity of adjacent limb segments because of the relatively high incidence of concurrent articular injuries. Therefore, the joints above and below the level of injury are always included in the films. They are filmed separately if the cassette is not large enough to accommodate the entire view. Similarly, when pathologic change is suspected in a joint, the long bones above and below are also imaged. This practice helps identify commonly associated injuries to the adjacent limb segments that might otherwise be missed.

Because bone is a three-dimensional object, a single two-dimensional radiograph cannot describe a fracture. To understand the position and direction of the fracture fragments, orthogonal views (images taken at 90 degrees to one another) must be obtained. A bone may appear minimally displaced in one plane but in another view may be significantly displaced ( Fig. 19.6 ). All extremities with deformity need to be rotated to the anatomic position before radiographs are taken to help decrease confusion in describing the fracture.

If at any point a reduction of a fracture or dislocated joint is performed, imaging should be obtained after the reduction to verify improvement in position or alignment or congruency of the joint reduction.

Some patients will have anatomic variants. If there is a question regarding the presence of an injury, imaging of the contralateral, uninjured side can be very useful in determining what is normal for that individual patient. When finer detail is necessary—such as in the assessment of an intraarticular injury or to confirm the findings of an equivocal radiograph—a CT scan should be ordered.

Magnetic resonance imaging (MRI) has become a particularly useful imaging modality. It is used to evaluate soft tissue, acute fractures, stress fractures, spinal cord injuries, and intra-articular disease. Its role in the trauma setting has expanded as well, and it is particularly helpful in the setting of spinal cord injury. More frequently, MRI is used in the outpatient setting to evaluate soft tissue injuries and pathologic lesions. MRI is now commonly used for the diagnosis of acute fractures when plain films are negative.

Shoulder

Frequently, an AP and lateral view of the shoulder is obtained with just rotation of the humerus and no movement of the x-ray tube. This is not an adequate assessment of the shoulder. True AP and lateral views of the shoulder must be taken in relation to the scapula because of the orientation of the joint ( Fig. 19.7 ). The most useful lateral view is an axillary radiograph ( Fig. 19.8 ). The tube is angled cephalad, with the plate on the superior aspect of the abducted shoulder. This view is often difficult to obtain because of pain or instability at the proximal end of the humerus. The Velpeau view is a modified axillary view that provides orthogonally equivalent images. While wearing a sling, the patient leans backward 30 degrees over the cassette on the table. The x-ray tube is placed above the shoulder, and the beam is projected vertically down through the shoulder onto the cassette ( Fig. 19.9 ). This allows the radiograph to be taken with the shoulder adducted and in a sling, allowing acquisition of the axillary images without the pain of shoulder abduction. A third option is the scapula “Y” view that obtains an image of the scapula down its long axis ( Fig. 19.10 ).

Elbow

AP and lateral views of the elbow provide visualization of most of the bone anatomy. Internal and external oblique views are included in a complete elbow series and allow better visualization of the medial and lateral epicondyles. On the lateral view, look for the fat pad sign or the sail sign for evidence of an occult fracture. The sail sign can be noted when hemarthrosis from an intraarticular fracture forces the anterior and posterior fat pads out of the coronoid and olecranon fossae, respectively. On radiography, the visualized fat pads resemble a sail ( Fig. 19.11 ). Although the anterior fat pad can be visualized in a normal elbow, the presence of a posterior fat pad sign is strongly suggestive of occult fracture and, if clinically appropriate, warrants a CT scan. A CT scan is sometimes ordered if there is a question of intraarticular extension, as this changes the operative plan. Another option is a traction view of the elbow, which can even be obtained prior to surgical prep.

Pelvis and Acetabulum

The pelvis is large in all planes and has a very unique anatomy. Because of that, radiographs remain an important tool of pelvic assessment despite the ubiquity of CT scans. Radiographs allow for the visualization of the entire pelvis at one time, which allows for the bony relationships to be assessed. The standard AP radiograph of the pelvis provides an overview to the structural integrity of the hips and pelvic ring. If pelvic disease is noted on this film or suspected from physical examination, further views are necessary. Judet views, or 45-degree oblique views of the pelvis, are used to evaluate the acetabula ( Fig. 19.12 ).

Similarly, inlet and outlet views of the pelvis allow closer examination of the sacroiliac joints and the sacrum itself, as well as identifying AP disruption in the pelvic ring. The inlet view is taken with the beam angled 60 degrees caudad, thus making the beam perpendicular to the pelvic brim. The sacral ala, displacement of the sacroiliac joints, and displacement of the pubic symphysis in the AP plane are easily seen. The outlet view is a 30-degree oblique view, with the tube angled cephalad. The sacrum is pictured en face, and the neural foramina are easily evaluated.

If it has not already been obtained as part of the trauma workup, pelvic CT should be ordered to evaluate fractures of the acetabula and sacrum. This allows detailed evaluation of the amount of articular involvement or displacement and of the presence of bone fragments within the joint. It also provides information about sacral displacement or neural foraminal involvement. Finally, it allows evaluation for intrapelvic hematoma. MRI has little role in acute, traumatic pelvic ring injury; however, it is the imaging modality of choice for suspected osteomyelitis or pelvic abscess.

Knee

AP, lateral, and internal or external oblique plain films allow visualization of most traumatic osseous abnormalities of the knee. If possible, standing films are useful for evaluating knee alignment and joint space narrowing. Imaging both knees on a single weight-bearing AP allows for easy comparison to the contralateral side. The lateral film can show an effusion, patellar fracture, posterior tibial plateau fracture, or tibial tubercle injury. If there is any doubt as to the degree of articular involvement, displacement, or depression, a CT scan should be ordered ( Fig. 19.13 ). Although MRI can be helpful in the acute setting, evaluation of ligamentous derangement is not urgent and can be deferred to the outpatient setting. In the setting of a knee dislocation, vascular injury should be assumed until proven otherwise. Serial measurements of the ABI are useful to monitor for vascular compromise, but vascular imaging in the form of CT angiography or MR angiography should be strongly considered in the setting of an acute knee dislocation.

Ankle

Most ankle injuries are rotational in nature, and a variety of injuries can be cause be the same rotational forces, depending on where the body fails. Like the forearm, the relationship between the tibia and fibula can be considered as a single joint that runs the length of the leg. Rotational injuries at the ankle can affect the proximal leg: energy that enters the medial ankle or leg when the body moves above a planted foot must exit at some point. That exit may be through the distal fibula at the level of the joint, or it may be at the top of the fibula. The distal tibia shaft may break instead of the ankle. Imaging must be ordered with sustained vigilance that the entire leg may be affected.

In the ankle, it is important to confirm congruency of the mortise. The stability of the mortise depends on bone and ligamentous support. With AP, mortise, and lateral radiographs, disruptions in the bone anatomy can be visualized directly. Although the ligamentous structures cannot be visualized directly, assumptions about their continuity can be made by evaluating the spaces between the bones. Three main parameters commonly used are the tibia-fibula overlap, tibia-fibula clear space, and medial clear space ( Fig. 19.14 ). When internally rotating the ankle from the AP to the mortise view, the medial clear space and tibia-fibula overlap will change. The tibia-fibula clear space should stay relatively the same.

While bimalleolar and trimalleolar ankle fractures are operative, isolated distal fibula fractures can potentially be treated conservatively with a splint or fracture boot. A radiographic stress exam should be performed when evaluating any distal fibula fracture. The ankle is stressed on the mortise x-ray. This can either be done manually or by using gravity. The latter is performed by laying the patient on the ipsilateral side with a stack of sheets under the lateral leg. This allows the affected ankle to hand freely to the lateral side. In a positive stress exam, either or both the medial clear space and the tibia-fibula clear space will widen. A positive stress x-ray is demonstrative of an unstable ankle joint that requires operative fixation.

As noted in other sections, articular injuries of the tibial plafond (pilon fractures) necessarily require a CT scan. One difference, however, is that pilon fractures almost always must be placed in an ex-fix for 7–14 days to allow for soft tissue recovery prior to definitive treatment. The CT scan should be deferred until after the ankle joint and the fracture fragments are distracted in an ex-fix.

Foot

When an injury of the foot is suspected, the workup should start with a standard series of AP, lateral, and oblique radiographs. However, because of the complex three-dimensional structure of the foot, this standard series of films may not be adequate to visualize certain bones. In the case of a calcaneus fracture, a Harris axial view should be added to evaluate the varus-valgus alignment of the tuberosity as well as any sagittal splits in the bone. Bohler angle—an angle formed by the bisection of a line drawn from the superior aspect of the calcaneal tuberosity to the superior aspect of the posterior facet and a line drawn from the tip of the anterior process to the superior aspect of the posterior facet—should be evaluated in the lateral view ( Fig. 19.15 ). A normal Bohler angle is between 20 and 40 degrees. A decrease in this angle usually indicates fracture, with depression of the posterior facet. When in doubt, films of the uninjured foot should be taken for comparison.

For fractures of the talus, the AP and lateral films should be evaluated for articular congruence at the tibiotalar, subtalar, and talonavicular joints. There are specialized views of the bone (e.g., Canale view for the talar neck and Broden view for evaluation of the subtalar joint); however, these views are radiology technician dependent. In many cases, if a fracture is seen on the AP or lateral view, a CT scan is a faster and more cost-effective way to evaluate the displacement pattern. If radiographs are negative or equivocal and the patient has evidence of fracture—ecchymosis, pain out of proportion to plain film findings, significant soft tissue swelling—a CT scan should be ordered. All but the most minimally displaced intraarticular fractures of the talus and calcaneus warrant a CT scan to define the fracture pattern and extent of articular displacement better. Except in the case of suspected osteomyelitis, MRI of the foot is of little use in the emergency setting.

Vascular Injuries

Angiography is another important modality used for the evaluation of extremity and pelvic injuries. It is indicated whenever signs of distal ischemia are noted in an extremity. In addition, it should be considered for a patient with pelvic fractures who is hemodynamically unstable. Knee dislocations are concerning because of the high incidence of associated vascular injury. There is a reported 18% to 30% rate of vascular injury after traumatic knee dislocation. Current recommendations for evaluation of the leg after a knee injury include serial vascular examinations, using both manual palpation of pulses and the ABI, followed by selective arteriography of patients with abnormal examination findings.

Initial Management

Care of musculoskeletal injuries begins in the prehospital phase of care. The extent of fracture and wound management differs with the level of training and experience of the first responders—laypeople, police, and emergency medical personnel. Therefore, it is essential that the initial treating physician perform a thorough assessment and begin initial management, including splinting and wound care.

Wound Management

After a thorough physical examination, treatment is begun immediately. All wound dressings and nontraction splints placed in the field should be removed by a single examiner to evaluate the degree of deformity and soft tissue injury. If an open fracture is suspected, tetanus prophylaxis and appropriate antibiotic prophylaxis should be given immediately. ^, Superficial contamination by dirt, gravel, or grass may be removed. Using sterile technique, wounds should be irrigated with sterile saline and mechanically debrided in the ED; however, this is expected to be cursory given the setting. A more thorough debridement will necessarily occur later in the controlled environment of the operating room. External bleeding in the extremities is controlled by direct manual pressure. Sterile saline solution or povidone-iodine–soaked dressings are then applied. After sterile dressings are placed over the wounds in the ED, they should remain in place until the time of operative irrigation and debridement. Immobilization is then undertaken in the same manner as for a closed injury.

Reduction and Immobilization

All displaced fractures and dislocations are gently reduced to reestablish limb alignment provisionally. If the patient’s condition allows, precise reductions are performed, and the extremities are splinted formally to maintain the fracture reduction. With time, the difficulty of reduction increases because of edema and muscle spasm. Therefore, reduction needs to be attempted as soon as possible and with the patient as relaxed as possible. Often, narcotic analgesics and sedatives are necessary, particularly with large joint dislocations. Muscle spasm can obstruct atraumatic reduction of these injuries. If a joint is still dislocated after adequate sedation and relaxation, general anesthesia may be necessary.

Reduction maneuvers follow the same principles for all fracture and dislocation types. First, in-line traction is applied to the limb. If the soft tissue envelope surrounding the fracture fragments is intact, in-line traction alone may produce satisfactory alignment through ligamentotaxis. In most cases, the deformity must be recreated and exaggerated to unhook the fractured ends. While still pulling traction, the mechanism of injury is reversed, and the fracture reduced. Neurovascular status is documented before and after any reduction maneuver or splint application. Once satisfactory reduction or alignment is achieved, it must be maintained by immobilization through casting, splinting, or continuous traction. The joints above and below the fracture must be included to prevent displacement. Postreduction radiographs are required to confirm alignment and rotation. Nondisplaced fractures are treated like displaced fractures, without reduction. Most nondisplaced fractures do not require surgical treatment. Splints are placed initially and then changed to circumferential casts after the swelling subsides.

Ligamentous injuries may also require immobilization. The joint is fully evaluated as described earlier, and a thorough neurovascular examination is performed on the limb. Frequently, pain, effusions, or hemarthroses occur; these represent intraarticular injury. Therapeutic aspiration of a traumatic hemarthrosis is not recommended because this can lead to iatrogenic infection. In addition, release of the pressure of the effusion can precipitate more bleeding. The limb is then immobilized and reevaluated after the acute pain and swelling decrease.

The rationale for immobilization is threefold. First, splinting, particularly with traction or compression devices, reduces bleeding by reducing the volume of the muscle compartments. Second, additional soft tissue injury may be averted, and the chance of converting a closed to an open fracture by sharp bone fragments is reduced. Third, immobilization of the fracture reduces the patient’s discomfort and facilitates transportation and radiographic evaluation of the patient. All fractures and dislocations are splinted or immobilized in the ED. Splints are usually fashioned from padded plaster or fiberglass. Different splinting techniques are used to immobilize each type of fracture. A volar or ulnar gutter splint is used for fractures of the hand. A sugar tong splint ( Fig. 19.16A–D ) is used for wrist or forearm fractures. This splint prevents flexion and extension at the wrist and elbow as well as pronation and supination of the forearm. Fractures about the elbow are placed in a posterior long arm splint. For humeral shaft fractures, a coaptation or posterior splint is used. When there is minimal swelling present with a humeral shaft fracture, a functional fracture brace may be applied in the ED. A short leg splint consisting of a posterior slab and a U or stirrup component ( Fig. 19.16E–H ) is used for disease of the foot and ankle. With the addition of side slabs crossing the knee, this splint can be extended into a long leg splint for tibial fractures or knee dislocations ( Fig. 19.16I and J ). Splints can be secured with a bias-cut stockinette, elastic wraps, or gauze bandage, provided they are wrapped in a nonconstrictive fashion.

For fractures that require reduction, it is important to mold the initial splint or cast to maintain the reduction. The natural tendency of many fractures is to displace back into their injured position. Three-point molding of the splint is required to maintain the reduction in the proper position. Common examples of molding include a slight valgus mold for humeral shaft fractures and a volarly directed mold for dorsally displaced distal radius fractures ( Fig. 19.17 ).

The role of circumferential casting in the acute setting is questionable. Because swelling of the injured extremity increases for 48 to 72 hours, a circular cast can be too constrictive and may lead to pressure necrosis or compartment syndrome. In select cases, in which a cast will be the definitive treatment (pediatric fractures or select nondisplaced fractures in adults), the initial circumferential cast can be applied and then cut longitudinally on two sides to allow swelling without splitting of the padding. This technique is called bi-valving the cast; it maintains a reduction more effectively than an open splint while still allowing soft tissue swelling.

Traction

Traction is used to immobilize fractures or dislocations displaced by muscle forces that cannot be adequately controlled with simple splints. The most common indications are vertical shear injuries of the pelvis, unstable hip dislocations, acetabular fractures, and fractures of the proximal femur or femoral shaft. ^, Traction may be applied through the skin using a Buck traction boot or through the bone using a skeletal traction pin placed through the bone distal to the fracture ( Fig. 19.18 ). Traction of more than 8 pounds through the skin for any extended period causes skin damage. Therefore, skin traction is practical only for geriatric hip fractures and pediatric injuries requiring limited distraction force. The Hare traction splint applies a distraction force through an ankle stirrup and can provide effective immobilization for femoral shaft fractures ( Fig. 19.19 ). It can be applied in the field and helps facilitate transport and mobilization, but it should be used only temporarily because of the risk of skin breakdown from the stirrup.

Skeletal traction may be maintained for longer periods with more weight than that possible with skin traction. It is applied using Steinmann pins or Kirschner wires. Up to 10% of body weight may be applied to a lower extremity skeletal traction pin. Radiographs of the anticipated pin site should be obtained before placement. Neurovascular structures must be avoided during placement of the pins. As a rule of thumb, pins should be placed from the side of the extremity containing the known structure at risk. This allows control over where the pin enters in relation to these structures. In the distal femur, the pin should be passed from medial to lateral to avoid the adductor hiatus containing the femoral artery and nerve. The pin should be placed parallel to the knee joint slightly proximal to the superior pole of the patella and in the midpoint of the bone on the lateral radiograph. In the proximal tibia, the pin should be passed from lateral to medial to avoid the common peroneal nerve passing around the fibular head. The ideal pin placement is parallel to the joint, approximately 2 cm distal and 2 cm posterior to the top of the tibial tubercle. In the calcaneus, the pin should be passed medial to lateral to avoid the neurovascular bundle passing around the medial malleolus. The pin should be placed in the tuberosity, parallel to the ankle joint, as far posterior and inferior as possible while still passing through good bone. Once the pins are placed, the skin is checked for tension, which is relieved with incisions if necessary. The wounds are then dressed with petrolatum gauze and sterile sponges. While pin track infections are a rare complication, they can lead to osteomyelitis or septic arthritis in the worst cases. ^, Pin site care should be performed twice daily with a half-strength hydrogen peroxide solution and sterile dressings.

The availability of an operating room and expected time to surgery should be considered before applying skeletal traction. A study by Even and colleagues prospectively evaluated 65 patients with diaphyseal femur fractures randomized to cutaneous (Buck’s) versus skeletal traction. All patients underwent fixation within 24 hours of hospitalization. There was no difference in preoperative pain control or intraoperative time to reduction between groups. For patients predicted to undergo operative fixation within 24 hours, application of cutaneous traction can avoid any unnecessary risks of ED traction pin placement. Polytrauma patients or those likely not to be taken in a timely manner to the operating room should have skeletal traction placed.