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Emergency Medicine Atlas > Part 1. Regional Anatomy > Chapter 11. Extremity Trauma > Upper Extremity >

Acromioclavicular Joint Separation

Associated Clinical Features

Injury to the acromioclavicular (AC) joint is a common finding in the ED, resulting from direct trauma with an adducted arm or indirectly from a fall on an outstretched arm with pressure directed to the joint (Fig. 11.1). There are three degrees of injury (Fig. 11.2). A first-degree injury is equivalent to a sprain. There is an incomplete tear of the ligament. Radiographs are negative. A second-degree injury consists of subluxation of the AC joint and disruption of the ligament. Subluxation of the clavicle from the acromion, of less than 50% the diameter of the clavicle, is only evident on stress radiographs. Complete disruption of the AC, coracoacromial, and coracoclavicular ligaments is a third-degree injury. Radiographs reveal more than 50% displacement of the clavicle from the acromion. All patients complain of pain at the joint site with moderate to severe amounts of swelling. Stress radiographs are obtained by suspending 5 to 10 lb of weight from each arm and taking a bilateral anteroposterior (AP) shoulder film. The joint space and any subluxation are easily visualized.

Figure 11.1

Acromioclavicular Joint Separation Subtle prominence of the left distal clavicle. The upward displacement of the clavicle is due to stretching or disruption of the suspending ligaments. (Courtesy of Frank Birinyi, MD.)

Figure 11.2

Acromioclavicular Joint Injuries Classification of acromioclavicular joint injuries. (Adapted with permission from Rockwood CA, Green DP, Bucholz RW: Rockwood and Green's Fractures in Adults, 3d ed. Philadelphia: Lippincott; 1991.)

Differential Diagnosis

Clavicular fracture, scapular fracture, rotator cuff injury, shoulder dislocation, contusion, or isolated coracoclavicular ligament damage can be confused with AC joint separation.

Emergency Department Treatment and Disposition

First- and second-degree injuries are treated with rest, ice, analgesics, and a simple sling until acute pain with movement is relieved. Third-degree injury treatment is controversial. Many experts advocate immobilization with a sling for 3 weeks, whereas others advocate operative repair. Orthopedic referral is essential for all third-degree injuries.

Clinical Pearls

1. The AC joint stress test is an accurate means of testing for AC joint separation. The patient is instructed to bring the arm across the chest and try to align the opposite shoulder with the elbow. The production of pain over the AC joint confirms the diagnosis.

2. Since first- and second-degree separations are managed conservatively, stress views rarely alter management.

Shoulder Dislocation

Associated Clinical Features

Anterior shoulder dislocations are the most common dislocation seen in the ED. They are caused by external rotation and abduction that disrupts the capsule and glenohumeral ligaments. The affected extremity is held in slight abduction and external rotation. Often, the patient supports the dislocated shoulder with the other arm. The acromion becomes prominent and there is a squared-off box-like appearance to the top of the shoulder. The rounded contour of the deltoid is lost (Fig. 11.3). These patients complain of shoulder pain and refuse to move the shoulder on the affected side. Many patients will appear diaphoretic and pale. A neurologic examination of the upper extremity should be performed to rule out associated injury, most commonly of the axillary nerve (sensation over the deltoid). Radiographic examination is necessary to evaluate for associated fracture (Fig. 11.4). Posterior shoulder dislocations are commonly missed because of subtle radiographic findings (Figs. 11.5 and 11.6). The arm is held internally rotated and adducted. There is no external rotation. On examination, a posterior prominence exists. Posterior dislocations commonly occur during seizures. The Hill-Sachs deformity (an impaction of the humeral head) can occur in a significant percentage (11 to 50%) of these patients.

Figure 11.3

Anterior Shoulder Dislocation This right anterior shoulder dislocation occurred when the patient fell while playing basketball. There is an obvious contour deformity as well as prominence of the acromion. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.4

Anterior Shoulder Dislocation Radiographic evaluation of this anterior shoulder dislocation demonstrates that the humeral head is not in the glenoid fossa but is located anterior and inferior to it. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.5

Posterior Shoulder Dislocation AP radiograph of this rare type of shoulder dislocation. Because of internal rotation of the greater tuberosity, the humeral head appears like a dip of ice cream on a cone, thus called the "ice cream cone sign." (Courtesy of Alan B. Storrow, MD.)

Figure 11.6

Posterior Shoulder Dislocation A scapular Y view of the same patient in Fig. 11.5 confirms the diagnosis. (Courtesy of Alan B. Storrow, MD.)

Differential Diagnosis

Acromioclavicular separation, fracture of the greater tuberosity, humeral fracture, and fracture of the humeral head are commonly mistaken for a shoulder dislocation prior to radiographic examination.

Emergency Department Treatment and Disposition

Closed reduction is the treatment of choice and may require conscious sedation. There are many methods to reduce shoulder dislocations, including Stimson, traction-countertraction, and external rotation. Neurovascular and radiographic examination should occur before and after reduction. The patient should be placed in a sling and swathe after reduction. The shoulder should remain immobilized for 2 to 5 weeks (shorter periods for older patients owing to their greater propensity to develop shoulder stiffness).

Clinical Pearls

1. Patients with a dislocated shoulder usually cannot touch the contralateral shoulder with the hand of the affected side.

2. Relaxation of the pectoral musculature is an excellent aid in shoulder reduction. This can be accomplished by manual massage of the muscle. Some patients can relax this muscle voluntarily when asked to do so (e.g., weightlifters).

3. Luxatio erecta (Fig. 11.7) is inferior glenohumeral dislocation. The humeral head is forced below the inferior aspect of the glenoid fossa. These patients present with the arm locked 180 degrees overhead.

Figure 11.7

Luxatio Erecta Hyperabduction may cause the relatively rare inferior dislocation known as luxatio erecta. The patient presents with the arm held in elevation and the humeral head may be palpated along the lateral chest wall. (Courtesy of Kevin J. Knoop, MD, MS.)

Biceps Tendon Rupture

Associated Clinical Features

Rupture of the biceps may occur anywhere along its route. It occurs most commonly in the dominant extremity of men between 40 and 60 years of age when an unexpected extension force is applied to the flexed arm. It may be associated with chronic bicipital tenosynovitis. When it occurs proximally, the patient notes a sharp pain in the bicipital groove and the muscle may be noted to contract within the arm (Fig. 11.8). It may be helpful to have the patient hold his or her arm abducted and externally rotated at 90 degrees. Flexion at the elbow will cause the biceps to move away from the shoulder. Rupture may also occur at the tendon insertion into the radial tuberosity at the elbow, often in an area of preexisting tendon degeneration. This diagnosis is made on the basis of a history of a painful, tearing sensation in the antecubital region. A snap or pop may also occur. The ability to palpate the tendon in the antecubital fossa may indicate partial tearing of the biceps tendon.

Figure 11.8

Biceps Tendon Rupture The biceps is noted to contract within the arm after biceps tendon rupture. (Courtesy of Daniel L. Savitt, MD.)

Differential Diagnosis

Muscle strain, partial tendon rupture, and deep venous thrombosis should be considered.

Emergency Department Treatment and Disposition

Nonoperative treatment consists of gentle range-of-motion exercises, anti-inflammatory medication, and physical therapy. This type of treatment results in restoring about 60% of normal strength of the biceps tendon. Operative treatment of proximal or distal ruptures is indicated for patients who wish to try to restore normal strength to the biceps tendon.

Clinical Pearls

1. Early surgical reattachment to the coracoid, bicipital groove, or radial tuberosity is recommended for optimal results.

2. Rupture in the belly of the biceps is treated conservatively.

Elbow Dislocation

Associated Clinical Features

Dislocations of the elbow can be anterior, posterior, medial, or lateral. All dislocations require immediate reduction to relieve pain and prevent circulatory compromise. Elbow dislocations are caused by a considerable amount of force, and approximately 40% have an associated fracture. Posterior dislocation is the most common (Fig. 11.9), occurring after a fall on an outstretched hand. The arm is extended and abducted. The elbow is held in a flexed position and is swollen, tender, and deformed. The olecranon is very prominent. Neurovascular status must be evaluated immediately because of associated injury. Anterior dislocations are rare. They occur if the elbow is in a flexed position and is hit from behind on the olecranon. The elbow is extended with the forearm supinated and elongated. The upper arm appears shortened. Injury to nerves and vessels is more common with anterior dislocation.

Figure 11.9

Posterior Elbow Dislocation This patient dislocated his elbow while playing basketball. Note the flexed position of the elbow and the prominence of the olecranon. (Courtesy of Frank Birinyi, MD.)

Differential Diagnosis

Contusion, radial or ulnar fracture, or supracondylar fracture of the humerus are commonly confused with an elbow dislocation until examined radiographically.

Emergency Department Treatment and Disposition

Most patients require analgesia and muscle relaxants prior to reduction. After reduction, the elbow should be immobilized in 90 to 120 degrees of flexion in a posterior splint and sling. Neurologic and radiographic examination should occur after any attempt at reduction. The patient should be observed in the ED for vascular compromise. Elbow dislocations with associated fractures may make closed reduction difficult and also leave the joint unstable. In these cases, consultation with an orthopedic surgeon is recommended prior to reduction attempts.

Clinical Pearls

1. Patients should not be placed in a circular cast because of the necessity for reexamination.

2. Factors that increase the index of suspicion for arterial injury include pulselessness prior to reduction, open dislocations, and concurrent serious traumatic injury.

3. The ulnar nerve is the most common nerve injured.

4. For posterior dislocations, palpate the two epicondyles and the tip of the olecranon. If they are in the same plane, a supracondylar fracture is likely. If the olecranon is displaced, a dislocation is likely.

Elbow Fractures

Associated Clinical Features

Direct trauma or fall on an outstretched hand may result in elbow fractures. The patient is usually unable to extend the elbow but has pain on supination/pronation. AP, lateral and oblique views of the elbow should visualize most elbow fractures. The radial head should be aligned with the capitellum on all views (Fig. 11.10). The presence of a "fat pad" sign on x-ray can be indicative of trauma. The anterior fat pad may be seen on normal radiographs but may be displaced anteriorly and superiorly by effusion or hemarthrosis (sail sign). The posterior fat pad is not normally visualized and if seen is indicative of effusion or hemarthrosis (Fig. 11.11).

Figure 11.10

Radiographic Elbow Relationships The anterior humeral line (1–2) should normally pass through the middle third of the capitellum. With an extension-type supracondylar fracture, this line will transect the anterior third of the capitellum or pass anterior to it. The radiocapitellar line (drawn through the center of the radius, 3–4) should also pass through the center of the capitellum. Disruption of this relationship may indicate fracture of the radial neck or dislocation.

Figure 11.11

Supracondylar Fracture This radiograph shows both a pronounced anterior fat pad (sail sign) and posterior fat pad indicative of a supracondylar fracture. (Courtesy of Alan B. Storrow, MD.)

Supracondylar fractures often occur in patients 5 to 10 years old. At this age the tensile strength of the collateral ligaments and the joint capsule of the elbow are greater than the bone itself. Neurovascular insult occurs in 7% of supracondylar fractures, with the radial, median, and ulnar nerves equally injured. Ulnar nerve impingement may occur, causing distal neuropraxia or injury.

Capitellum fractures occur from direct forces, a fall on an outstretched arm, or as an indirect result of posterior elbow dislocation. With a force directed at the radial head, shearing of the capitellum causes anterior displacement of the fracture segment. Radiographically, the joint capsule depicts a swelling along the anteriorly displaced fragment. This fracture is commonly associated with fractures of the radial head, which are common but may be subtle and require a high index of suspicion.

Differential Diagnosis

Posterior elbow dislocation, nursemaid's elbow, and inter- or transcondylar fractures should be considered.

Emergency Department Treatment and Disposition

Treatment of supracondylar fractures is influenced by angulation and displacement as well as associated soft tissue injuries (especially neurovascular). Adult patients usually require surgical intervention. In general, an orthopedic consultant best handles decisions regarding reduction of significantly angulated and displaced fractures. If neurovascular compromise exists, the emergency physician may need to apply forearm traction to reestablish distal pulses. If the pulse is not restored with traction, emergent operative intervention for brachial artery exploration or fasciotomy is indicated. The indications for primary open reduction are (1) those fractures in which there is inability to obtain a satisfactory closed reduction; (2) vascular injury; or (3) an associated fracture of the humerus or forearm in the same limb. In children, nondisplaced, nonangulated fractures can be splinted (90 degrees of flexion); angulated fractures require reduction and splinting; and displaced fractures require reduction and percutaneous pinning on an urgent basis, within 12 to 24 h. Fractures of the capitellum and radial head are treated with immobilization in a posterior long arm splint with the elbow in 90 degrees of flexion and the forearm in supination, analgesics, and control of swelling. Complications of displaced capitellum fractures include arthritis, avascular necrosis, and decreased range of motion. More severe fractures may need radial head excision to prevent malunion and joint malfunction. Patients with uncomplicated fractures may begin range-of-motion exercises within 3 to 7 days to reduce the risk of permanent loss of elbow motion from joint contracture. Intraarticular fractures, which may require radial head excision or fixation, should be referred to an orthopedist within 1 week for definitive management.

Clinical Pearls

1. Ten percent of children with supracondylar fractures temporarily lose their radial pulse due to joint swelling after injury. This usually resolves and does not present long-term sequelae.

2. Capitellum and radial head fractures often occur together.

3. Bleeding around the elbow raises suspicion of an open fracture or open joint and requires urgent orthopedic consultation.

4. The presence of a joint effusion with a history of trauma is presumptive evidence of a fracture.

Forearm Fractures

Associated Clinical Features

Fractures of the wrist and elbow usually involve a fall onto the outstretched arm, while fractures of the forearm shaft are more commonly the result of a direct blow. Injury to one of the bones of the forearm is often associated with fracture or dislocation of the other; therefore one must examine joints above and below involved bones both radiologically and clinically when injury to one forearm bone is identified. AP and lateral views of the wrist, forearm, and elbow are required when a forearm fracture is suspected. Functional deficits in the hand are important clues to identification of occult injury to forearm nerve and vascular structures that could require immediate surgical intervention. Monteggia's fracture-dislocation (Figs. 11.12, 11.13) is an ulnar fracture (usually proximal third) with associated proximal dislocation of the radial head. Dislocation is associated with about 7% of ulnar fractures. Forearm shortening can be noted, and significant forearm swelling is often present. Such a fracture is associated with significant radial nerve injury in 17% of cases.

Figure 11.12

Monteggia's Fracture Patients with a Monteggia's fracture present with swelling and pain in the forearm and often a palpable radial head in the antecubital fossa. (Courtesy of Alan B. Storrow, MD.)

Figure 11.13

Monteggia's Fracture Radiograph A Monteggia's fracture is defined by a fracture of the proximal one-third of the ulna combined with dislocation of the radial head. (Courtesy of Alan B. Storrow, MD.)

Galeazzi's fracture-dislocation is a fracture of the distal one-third of the radius with dislocation of the distal radioulnar joint. It occurs three times more often than a Monteggia fracture. Tenderness over the distal radioulnar joint is noted, in addition to swelling, tenderness, and possibly deformity at the fracture site.

Isolated fractures of the middle ulna may result from direct trauma and are termed nightstick fractures. High-energy injuries to the forearm may result in fractures of both the radius and ulna at midshaft, resulting in a grossly deformed and unstable injury.

Differential Diagnosis

Simple contusion, compartment syndrome, and muscular injuries should be considered.

Emergency Department Treatment and Disposition

Both Monteggia's and Galeazzi's fracture-dislocations require orthopedic consultation and are treated with immobilization in a long-arm splint (with elbow flexed at 90 degrees). The forearm is placed in a neutral position for a Monteggia fracture and pronated for Galeazzi fracture. Treatment is usually surgical for both injuries, although children may be treated by reduction and casting.

Clinical Pearls

1. Any ulnar fracture with greater than 10 degrees of angulation or with a bony fragment displaced more than 50% of the bones' diameter is considered displaced and requires surgical correction.

2. Isolated proximal ulnar fractures are rare. Always suspect a Monteggia fracture-dislocation and closely examine the radial head for dislocation or other evidence of injury. A line drawn through the radial shaft and head must align with the capitellum in all views to exclude dislocation (see Fig. 11.10).

3. A distal ulnar styloid fracture, if found, can be a clue to a Galeazzi's fracture. It is associated with Galeazzi's injury in approximately 60% of cases.

4. Fractures of the forearm may result in compartment syndrome.

Fractures of the Distal Radius

Associated Clinical Features

Falls on an outstretched arm are common and the forces involved with this mechanism of injury are often significant enough to break both the radius and the ulna. Open fractures are common, and one must look closely for overlying soft tissue injury. Distal radial fractures account for 17% of all fractures treated in the ED. In the elderly they are usually extraarticular metaphyseal fractures, whereas in younger patients they are usually intraarticular with displacement of the joint surface. There are four types of radial fractures, associated with commonly known eponyms: Colles' fracture, Smith's fracture, Barton's fracture and Hutchinson's (chauffeur's) fracture.

A Colles' fracture is dorsal displacement and angulation of the distal radius and is the most common wrist fracture in adults. Colles' fracture is usually an extension injury associated with significant bony displacement and obvious "dinner fork" deformity on physical examination (Fig. 11.14).

Figure 11.14

Colles' Fracture The classic dinner-fork deformity is demonstrated in this photograph. The distal forearm is displaced dorsally. (Courtesy of Cathleen M. Vossler, MD.)

Smith's fracture is a distal metaphyseal fracture with volar displacement and angulation. This usually results from a blow to the dorsum of the wrist or hand or a hyperflexion injury. Radiography reveals distal volar displacement. Examination reveals deformity and pain in the distal radius (Figs. 11.15, 11.16, 11.17).

Figure 11.15

Smith's Fracture A Smith's fracture is sometimes described as a reverse Colles'. (Courtesy of Frank Birinyi, MD.)

Figure 11.16

Smith's Fracture The radiograph reveals volar displacement of the distal radial fragment together with the bones of the wrist and hand. (Courtesy of Frank Birinyi, MD.)

Figure 11.17

Distal Forearm Fractures These illustrations depict three different types of distal forearm fractures: Smith's, Barton's, and Hutchinson's. (Adapted from Simon R: Emergency Orthopedics: The Extremities. Norwalk, CT: Appleton & Lange; 1987, pp 118–119.)

Barton's fracture (Fig. 11.17) is a fracture of the dorsal rim of the distal radius. The rim of the distal radius, commonly a triangular bone fragment, is displaced dorsally. It may be associated with dislocation of the radiocarpal joint.

A chauffeur's or Hutchinson's fracture (Fig. 11.17) is an avulsion fracture of the distal radial styloid that occurs from a force transmitted from the scaphoid to the styloid. It may be considered an unstable fracture secondary to an associated ligamentous injury.

Emergency Department Treatment and Disposition

ED evaluation and management of these fractures is similar because certain fracture characteristics define instability. Comminuted, displaced, unstable, and open fractures or those with neurologic or vascular compromise require prompt orthopedic attention. In addition, fractures with greater than 20 degrees of angulation or with more than 1 cm of shortening are potentially unstable and deserve aggressive management. Initial immobilization can be accomplished with a double sugar-tong splint. Stable fractures respond well to closed reduction and casting for 6 to 8 weeks. Most closed Colles' and Smith's fractures can be managed with closed reduction in the ED with use of finger traps, local anesthesia via hematoma or Bier block, and gentle manipulation to restore anatomic alignment. Detailed discharge instructions should be given regarding symptoms of median nerve impingement, including paresthesias and hand weakness, which should prompt return to the ED.

Clinical Pearls

1. All fractures of the distal radius must be evaluated for median nerve function before and after reduction.

2. Colles' fractures warrant a high index of suspicion for intraarticular injury, especially when a radial styloid fracture is noted.

3. With a Hutchinson's fracture, associated ligamentous injuries should be sought, especially scapholunate dissociation and perilunate and lunate dislocation.

Carpal and Carpometacarpal Dislocations

Associated Clinical Features

Carpal and carpometacarpal dislocations are serious wrist injuries usually occurring from hyperextension. Their diagnosis requires careful physical and radiographic examination. Patients complain of decreased range of motion, pain, swelling, and ecchymosis.

Lunate dislocation (Fig. 11.18) can occur in a volar or dorsal position with the lunate displaced relative to the other carpal bones (Fig. 11.19). The normal lunoradial relationship is disrupted. The median nerve is most commonly involved and should be evaluated.

Figure 11.18

Lunate Dislocation This photograph demonstrates swelling associated with a volar lunate dislocation. (Courtesy of Cathleen M. Vossler, MD.)

Figure 11.19

Lunate Dislocation Radiographic examination of a dorsal lunate dislocation. (Courtesy of Cathleen M. Vossler, MD.)

If the lunoradial articulation is intact and the other carpal bones are dislocated relative to the lunate, it is termed a perilunate dislocation. (Figs. 11.20, 11.21).

Figure 11.20

Perilunate Dislocation This patient sustained a fall on his outstretched hand with impact on the palm. The force transmitted through the radius and lunate disrupted the lunate-capitate articulation. The capitate and other carpal bones were driven posteriorly with respect to the lunate, resulting in the prominent dorsal deformity. (Courtesy of Alan B. Storrow, MD.)

Figure 11.21

Perilunate Dislocation This slightly oblique radiograph of the patient in Figure 11.20 reveals dorsal displacement of the carpal bones in relation to the lunate. The lunate does have slight anterior rotation, although its relationship with respect to the distal radius is intact. (Courtesy of Alan B. Storrow, MD.)

Another potentially serious injury is scapholunate dislocation, often mistakenly diagnosed as a sprained wrist. Although the physical examination may be unremarkable except for wrist pain, an anteroposterior (AP) radiograph reveals a widening of the scapholunate joint space (Fig. 11.22). This space is normally less than 3 mm. A space of 4 mm or greater should prompt suspicion of this problem. In addition, the lateral radiograph may reveal an increase of the scapholunate angle to greater than 60 to 65 degrees (normal 45 to 50 degrees).

Figure 11.22

Scapholunate Dislocation Radiographic evidence of a scapholunate dislocation. Note the widened scapholunate joint space. This injury is often misdiagnosed as simple wrist sprain. (Courtesy of Alan B. Storrow, MD.)

All these dislocations may present with concomitant fractures of the carpal bones or distal forearm. A scaphoid fracture is particularly troublesome, since misdiagnosis of this problem can result in later delayed healing or avascular necrosis (Fig. 11.23). This potentially serious problem is due to lack of a direct blood supply to the proximal portion of the bone. Tenderness on palpation of the anatomic snuffbox, or with axial loading, is a common finding. Unfortunately, negative radiographs do not rule out an occult scaphoid fracture.

Figure 11.23

Scaphoid Fracture Fracture of the wrist, or middle third, of the scaphoid. These injuries can be associated with delayed healing and avascular necrosis. (Courtesy of Alan B. Storrow, MD.)

Carpometacarpal dislocations are fortunately rare, since they are often devastating injuries requiring extensive repair (Fig. 11.24). Functional loss is marked and common.

Figure 11.24

Carpometacarpal Dislocation This uncommon injury occurred after a fall from a ladder onto an outstretched hand. Note the prominent deformity of the proximal metacarpals, II to IV, on the dorsal hand. Also note the normal prominence of the ulnar styloid, which helps the examiner in anatomic localization of the dislocation (A). Radiographic examination of the patient depicted above (B). (Courtesy of Alan B. Storrow, MD.)

Differential Diagnosis

Arthritis, carpal tunnel syndrome, and joint infections should be considered in patients with wrist pain.

Emergency Department Treatment and Disposition

Initial management includes adequate radiographic evaluation followed by ice, elevation, and splinting. Referral to a hand specialist is essential for adequate reduction and long-term care.

Clinical Pearls

1. A true lateral wrist radiograph best demonstrates a lunate dislocation by exhibiting the usual cup-shaped lunate bone as lying on its side and displaced either dorsally or volarly.

2. On lateral wrist radiographs, the metacarpal, capitate, lunate, and radius should all be aligned so that a line drawn through the long axis will bisect all four bones including the lunate. If this is not found, then some element of dislocation, subluxation, or ligamentous instability exists.

3. Patients in whom there is a clinical suspicion of an occult scaphoid fracture (anatomic snuff-box tenderness or axial load tenderness of the thumb without radiologic evidence of fracture) should receive a thumb spica splint and a repeat examination in 7 to 10 days.

Clenched Fist Injury

Associated Clinical Features

The clenched fist injury classically occurs during a fight when the metacarpophalangeal (MCP) joint contacts human teeth, resulting in a laceration in the skin (Fig. 11.25). Many patients will not divulge the true circumstances surrounding the injury; therefore all wounds at the MCP joint are considered a clenched fist injury until proven otherwise. Once these wounds occur, the inoculated organisms are sealed in a warm, closed environment, allowing rapid spread and destruction. Serious complications can result, including infection, loss of function, and amputation. Most wounds are polymicrobial. Patients who present initially may have little evidence of intra-articular injury on physical examination, whereas those who present more than 18 h after injury are more likely to have evidence of infection, including pain, swelling, erythema, and purulent drainage.

Figure 11.25

Clenched Fist Injury The small lacerations seen in this photograph were sustained from human teeth during a fight. Note the subtle black ink bar stamp across the proximal metacarpals of the right hand; this may reveal a clue about the wound's etiology. (Courtesy of Lawrence B. Stack, MD.)

Differential Diagnosis

Abrasions or lacerations secondary to a source other than human teeth can be mistaken for a clenched fist injury.

Emergency Department Treatment and Disposition

All wounds should be irrigated, debrided, explored, elevated, and immobilized. Patients should receive antibiotics directed at both oral and skin flora. Tetanus prophylaxis is given if needed. Radiographs should be obtained to evaluate for fractures and any foreign bodies remaining in the wound. These wounds should never be closed initially. All patients require careful follow-up with a hand specialist. Reliable patients who present early, without evidence of infection or significant medical history (e.g., diabetes), and no involvement of bone, joint, or tendon may be treated on an outpatient basis. They must return in 24 h for a wound check, sooner if any signs of infection develop. Any patient who does not meet these requirements must be hospitalized for intravenous antibiotics and wound care.

Clinical Pearls

1. Complications include cellulitis, lymphangitis, septic arthritis, abscess formation, osteomyelitis, and tenosynovitis.

2. All wounds need to be examined in full flexion and extension so that tendon injuries are not missed. A tendon injury sustained with the fingers flexed will be missed if the hand is examined only in extension due to the retraction of the tendon with extension.

Boxer's Fracture

Associated Clinical Features

A boxer's fracture is a metacarpal neck fracture of the fifth and sometimes fourth digit, which commonly occurs after a direct blow to the metacarpophalangeal joints of the clenched fist. The proximal metacarpal bone is angulated dorsally and the metacarpal head is angulated volarly. On physical examination, the "knuckle" is missing and can be palpated on the volar surface (Figs. 11.26, 11.27). Any associated laceration should be considered secondary to impact with human teeth ("fight bite," see "Clenched Fist Injury" Fig. 11.25).

Figure 11.26

Boxer's Fracture This boxer's fracture occurred when the patient punched a wall with his hand. There is loss of the "knuckle" when the dorsum of the hand is examined, especially noticeable when the patient makes a fist. (Courtesy of Cathleen M. Vossler, MD.)

Figure 11.27

Boxer's Fracture Radiographic examination reveals a fracture through the neck of the metacarpal and volar displacement of the fractured segment. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Fracture of the metacarpal head or metacarpal shaft, hematoma, sprain, clenched fist injury, and metacarpophalangeal dislocation are often mistaken for a boxer's fracture until radiographic evaluation is performed.

Emergency Department Treatment and Disposition

Prior to reduction, the injury must be evaluated for rotational malalignment. This is easily done by having the patient place all fingers in the palm; all fingers should point to the scaphoid bone (Fig. 11.28). Rotational deformities of greater than 15% require reduction. An ulnar nerve block provides sufficient anesthesia for the fifth metacarpal, but median and radial nerve blocks should be used for the other metacarpals. Hematoma block can be used as an alternative. Once adequate anesthesia is achieved, reduction can be attempted. A nondisplaced nonangulated fracture requires no reduction. Treatment includes ice, elevation, and immobilization in a gutter splint. For reduction, the distal interphalangeal (DIP), proximal interphalangeal (PIP), and metacarpophalangeal (MCP) joints are all held in flexion at 90 degrees. Pressure is exerted on the proximal phalanx, directed upward to push the metacarpal head dorsally back into position. At the same time, the metacarpal shaft is stabilized with pressure on the dorsum over the shaft. The patient should be splinted with the MCP at 90 degrees of flexion. Postreduction radiographs are necessary to ensure adequate reduction. Early follow-up (within 7 days) with a hand specialist is essential, since simple splinting may not adequately maintain proper reduction and fractures with higher degrees of angulation and instability may require fixation.

Figure 11.28

Rotational Deformity Malpositioning of the right fifth digit due to a boxer's fracture. Normally, all the digits point toward a single spot on the scaphoid. (Courtesy of Alexander T. Trott, MD.)

Clinical Pearls

1. Fractures of the second and third metacarpal neck will not tolerate any angulation and require orthopedic referral for anatomic reduction. Fractures of the fourth and fifth metacarpal neck can tolerate up to 30 and 50 degrees of angulation, respectively, before function is impaired.

2. Subtle malrotation can be recognized by looking at the alignment of the nail beds with the digits flexed. Complications include collateral ligamentous damage, extensor injury damage, and malposition or clawing of the fingers secondary to incomplete reduction.

Peripheral Nerve Injury

Associated Clinical Features

Ulnar nerve injury results in the classic claw-hand deformity (Fig. 11.29) because of the wasting of small hand muscles. The deformity is formed by hyperextension of the metacarpophalangeal joint and flexion at the proximal and distal interphalangeal joints of the fourth and fifth digits. There is wasting of the interosseous and hypothenar muscles, as well as the hypothenar eminence (Fig. 11.30). The patient is unable to abduct or adduct the digits.

Figure 11.29

Claw Hand This photograph demonstrates the claw-hand appearance resulting from median and ulnar nerve injury. Note metacarpophalangeal joint hyperextension. (Courtesy of Daniel L. Savitt, MD.)

Figure 11.30

Claw Hand Atrophy of the thenar and hypothenar eminences also occurs as a result of damage to the median and ulnar nerves, respectively. Note the concavity to the hypothenar eminence. (Courtesy of Cathleen M. Vossler, MD.)

Median nerve damage also results in the claw-hand deformity, but to the second and third digits. Damage to the proximal portion of the nerve results in weakness of wrist flexion, forearm pronation, thumb apposition, and flexion of the first three digits. Atrophy of the thenar eminence also occurs. There is a sensory loss over the area of distribution for each nerve. These findings are not seen acutely but are chronic signs from an old injury.

Wrist drop is the most common symptom seen with radial nerve damage, occurring in situations of acute compression. It is frequently referred to as Saturday night palsy (as when a person who has been drinking alcohol falls asleep on an arm or with the arm over a chair and there is temporary damage to the nerve).

Differential Diagnosis

Rheumatoid arthritis, osteoarthritis, and undiagnosed proximal (cervical osteophyte) or distal (carpal tunnel syndrome) entrapment syndromes can be mistaken for peripheral nerve injury.

Emergency Department Treatment and Disposition

Treatment is aimed at recognizing the underlying cause of the nerve damage. Such causes include laceration of the nerve, compression from swelling, or hematoma formation. In the ED, splinting and appropriate referral is the treatment.

Clinical Pearl

1. Long-term nerve injury results in muscle wasting. Prior to any nerve damage, the thenar and hypothenar eminences have a full appearance. This is lost in patients with nerve damage. Initially, there is flattening of each eminence, followed by a concave or hollow appearance.

Bennett's and Rolando's Fractures

Associated Clinical Features

These patients complain of pain, swelling, and decreased range of motion at the base of the thumb (Fig. 11.31). Bennett's fracture is an intraarticular fracture at the ulnar aspect of the base of the first metacarpal with disruption of the carpometacarpal joint (Fig. 11.32). The first metacarpal is displaced radially and proximally, with subluxation or complete dislocation (Fig. 11.33). Rolando's fracture is an intraarticular comminuted fracture at the base of the first metacarpal, with dorsal and volar fragments resulting in a Y- or T-shaped intraarticular fragment (Fig. 11.34).

Figure 11.31

Bennett's Fracture Bennett's fracture involves the base of the first metacarpal. The digit is swollen and ecchymotic over the affected area. (Courtesy of Daniel L. Savitt, MD.)

Figure 11.32

Bennett's Fracture Radiographic examination of a Bennett's fracture illustrates an intraarticular fracture at the base of the first metacarpal with the metacarpal displaced radially and proximally. (Courtesy of Cathleen M. Vossler, MD.)

Figure 11.33

Intraarticular Fractures of the First Metacarpal Base (A). An intraarticular fracture at the base of the first metacarpal with radial and proximal displacement is a Bennett's fracture (B). A comminuted intraarticular fracture at the base of the first metacarpal is a Rolando's fracture (C).

Figure 11.34

Rolando's Fracture Note the comminuted intraarticular fracture at the base of the first metacarpal. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Sprain, fracture of the first metacarpal shaft, or a gamekeeper's thumb (disruption of the ulnar collateral ligament of the metacarpophalangeal joint) are commonly mistaken for Bennett's or Rolando's fracture prior to radiographic evaluation.

Emergency Department Treatment and Disposition

The treatment of these fractures in the ED consists of ice, elevation, and immobilization in a thumb spica splint and early referral to a hand specialist. These fractures generally require operative reduction and fixation.

Clinical Pearls

1. Carpometacarpal dislocations are frequently difficult to reduce and require open reduction and fixation approximately 50% of the time.

2. Osteoarthritis is a common long-term complication, even after optimal management.

Boutonnière and Swan Neck Deformities

Associated Clinical Features

The boutonnière deformity is a result of injury or disruption to the insertion of the extensor tendon on the dorsal base of the middle phalanx. Common causes of this problem are proximal interphalangeal (PIP) joint contusion, forceful flexion of the PIP joint against resistance, and palmar dislocation of the PIP joint. Initially, a deformity may be absent but will develop over the course of time if the injury remains untreated. The lateral bands sublux and exert a proximal pull on the middle phalanx. The result is flexion of the PIP joint and extension of the DIP joint (Figs. 11.35, 11.36). Radiographically, a small fragment of bone may be visualized at the proximal portion of the dorsal aspect of the middle phalanx.

Figure 11.35

Boutonnière Deformity This depiction of a boutonnière deformity illustrates the rupture of the central slip and the resultant subluxation of the lateral bands. The subluxation exerts a pull on the middle phalanx resulting in the deformity.

Figure 11.36

Boutonnière Deformity A boutonnière deformity of the fourth digit. Note the flexion of the PIP joint and the extension of the DIP joint. (Courtesy of E. Lee Edstrom, MD.)

Swan-neck deformity occurs as a result of the shortening of interosseous muscles secondary to systemic diseases such as rheumatoid arthritis. The digit is contorted with hyperextension of the PIP and flexion of the distal interphalangeal (DIP) and metacarpophalangeal (MCP) joints (Fig. 11.37).

Figure 11.37

Swan-Neck Deformity A swan-neck deformity of the index finger. Note the hyperextension of the PIP joint and the flexion of the DIP joint. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Fracture, dislocation, or tendon damage can be mistaken for a boutonnière or swan neck deformity.

Emergency Department Treatment and Disposition

In dealing with a closed injury resulting in a boutonnière deformity, immobilization of the PIP joint in extension is adequate. Splinting the MCP and DIP joints is not necessary. The splint should be used for 4 weeks, at which point active range of motion can start. Open injuries must be carefully explored and repaired. Swan-neck deformities are treated by splinting the digit to prevent further deformity. Both deformities require referral to a hand specialist.

Clinical Pearls

1. Boutonnière deformity generally develops weeks after the initial injury as the lateral bands contract; therefore, it is frequently missed in the ED. Early diagnosis can be made with the proper examination of the finger. The digit should be adequately anesthetized and then examined for range of motion and joint stability.

2. Any injury involving the dorsal PIP surface should be reexamined for development of a boutonnière deformity after 7 to 10 days.

3. Surgical repair may be required for cases where conservative therapy yields inadequate results.

High-Pressure Injection Injury

Associated Clinical Features

A large number of commercial devices are able to deliver liquids and gases at high pressures. Occasionally, substances from these devices are injected into the body, especially the upper extremities. The most common devices include spray guns, diesel injectors, and hydraulic lines. The injury occurs when the device accidentally fires during cleaning or mishandling. The injury can be very misleading if seen soon after the event. On early examination, a small puncture wound or no apparent break in the skin may be found, with minimal swelling. Swelling and pain increase over time (Fig. 11.38). Vascular compromise can occur directly from compression secondary to swelling or from the inflammatory response that the body produces to the materials injected. The injected material tends to spread along fascial planes, so the extent of injury can be quite misleading and is often subtle on initial presentation.

Figure 11.38

High-Pressure Injection Injury This photograph illustrates injury incurred by a grease gun. The patient was cleaning the device and the gun accidently discharged into his hand. Note the swelling and erythema. The patient was taken to the operating room for initial debridement. (Courtesy of Richard Zienowicz, MD.)

Differential Diagnosis

Puncture wound, hematoma, or tenosynovitis can be confused with a hydraulic pressure injury.

Emergency Department Treatment and Disposition

Immediate operative debridement is the treatment of choice. Therefore, early consultation with a hand specialist is necessary. Radiographic examination evaluates for fracture and may outline spread of injected material. Tetanus and broad-spectrum antibiotics should be administered. The affected extremity should be elevated and splinted.

Clinical Pearls

1. Do not be misled by the "benign" appearance of the initial injury.

2. Delays in treatment can lead to compartment syndrome.

3. Digital blocks are contraindicated because of the potential for increased tissue pressure and compromise of tissue perfusion.

Phalangeal Dislocations

Associated Clinical Features

Phalangeal dislocations are common and can occur at all three finger joints. Distal interphalangeal (DIP) dislocations are the rarest but can occur when a force is applied to the distal phalanx. Gross deformity is noted on examination, with the distal phalanx generally displaced dorsally. Proximal interphalangeal (PIP) dislocations (Figs. 11.39, 11.40) are common and easily reducible. These are generally dislocated dorsally, caused by hyperextension, and may have associated damage to the volar plate (Fig. 11.41). PIP volar dislocations can be irreducible secondary to rupture of the extensor tendon or herniation of the proximal phalanx through the extensor mechanism, both requiring operative repair. Metacarpophalangeal (MCP) joint dorsal dislocations are often due to hyperextension.

Figure 11.39

Phalangeal Dislocation This patient dislocated the long finger PIP joint during an altercation. The PIP joint is displaced dorsally with an obvious deformity. (Courtesy of Cathleen M. Vossler, MD.)

Figure 11.40

Phalangeal Dislocation This photograph illustrates medial angulation of the ring finger, suggesting PIP dislocation. (Courtesy of Daniel L. Savitt, MD.)

Figure 11.41

Volar Plate Injury This photograph demonstrates the subtle PIP swelling and ecchymosis of the third (long) digit often seen with a volar plate injury (A). Hyperextension injuries cause disruption of the volar plate and result in swelling, ecchymosis, and tenderness along the volar aspect of the joint. These injuries are initially treated conservatively with splinting, but if they are unstable, operative repair is required. (Courtesy of Daniel L. Savitt, M.D.) Radiographic examination of the digit reveals a small fragment on the proximal volar surface of the PIP joint (B). (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Phalangeal fracture, metacarpal fracture, tendon damage, ligamentous injury, or boutonnière deformity can be confused with a phalangeal dislocation.

Emergency Department Treatment and Disposition

Digital nerve block is appropriate anesthesia for the PIP and DIP joints. Ulnar, median, or radial nerve blocks are necessary for the MCP joints. Reduction with splinting is the treatment of choice. Reduction is accomplished via hyperextension of the joint with concurrent application of horizontal traction. Flexion at the MCP joint will facilitate reduction of distal joints. Postreduction radiographs are necessary to ensure adequate reduction. The DIP joint should be splinted in slight flexion and the PIP joint in 20 degrees of flexion for 3 to 5 weeks, depending on the degree of ligamentous damage. Hand specialist follow-up is mandatory.

Clinical Pearls

1. All joints should be tested for instability after reduction, using a digital nerve block to facilitate testing.

2. PIP joint volar dislocation can be unstable, requiring open reduction and internal fixation.

3. Joint dislocations that have volar plate entrapment may be impossible to reduce and require surgical repair for successful reduction.

Mallet Finger

Associated Clinical Features

Mallet finger commonly occurs after the distal finger, specifically the distal interphalangeal (DIP) joint, is forcibly flexed, as from a sudden blow to the tip of the extended finger. This injury represents complete avulsion or laxity of the extensor tendon from the proximal dorsum of the distal phalanx (Fig. 11.42). The patient presents with an inability to extend the distal phalanx, and it remains in a flexed position (Fig. 11.43). On radiograph, a small chip fragment on the dorsum at the DIP joint may be visualized.

Figure 11.42

Mallet Finger This photograph depicts a mallet finger. The distal phalanx is held in flexion and the patient is unable to extend it. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.43

Mallet Finger This illustration demonstrates that the unopposed flexion of the DIP joint is secondary to the complete tear of the tendon (A), or an avulsion of a small chip fragment (B).

Differential Diagnosis

Intraarticular fracture of the distal phalanx, distal tuft fracture, or extensor tendon laceration can be confused with a mallet finger.

Emergency Department Treatment and Disposition

A closed mallet finger without involvement of the joint can be treated by splinting the DIP joint in extension to mild hyperextension. True hyperextension is to be avoided. This splint should be worn for 6 to 8 weeks, at which point active range of motion begins. There is no need to splint the other joints. Motion of the PIP joint should not be blocked with the splint. Hand surgery follow-up is required.

Clinical Pearls

1. During follow-up, some patients exhibit hyperextension of the distal phalanx while out of the splint. This is due to a weakness in the volar plate. These patients should be splinted with the DIP joint in flexion and followed closely.

2. Avulsion of a significant portion of the articular surface (more than one-third) may require open reduction with internal fixation by a hand surgeon.

Subungual Hematoma

Associated Clinical Features

A subungual hematoma is a collection of blood found underneath the nail, usually occurring secondary to trauma to the distal fingers (Fig. 11.44). These lesions can be quite painful because of pressure beneath the nail. There can also be swelling, tenderness, and a decreased range of motion of the associated finger. Associated injuries include nail bed trauma (Fig. 11.45) and distal tuft fractures.

Figure 11.44

Subungual Hematoma This subungual hematoma occurred after the patient hit his finger with a hammer. The hematoma covers approximately 50% of the subungual area. (Courtesy of Margaret P. Mueller, MD.)

Figure 11.45

Nail Bed Laceration Bleeding from a nail bed laceration causes a subungual hematoma. This image depicts a nail bed laceration seen after removal of the nail. (Courtesy of Alan B. Storrow, MD.)

Differential Diagnosis

A nail bed melanoma may resemble a subungual hematoma and is differentiated from a hematoma by lack of a history of recent trauma and subsequent appearance of the "lesion."

Emergency Department Treatment and Disposition

A radiograph should be done to evaluate for possible fracture. If the subungual hematoma covers less than 25%, trephining the nail with a sterile needle or electrocautery is adequate to relieve pain by allowing drainage. Management of larger hematomas is somewhat controversial. Some authors advocate removal of the nail if the hematoma covers more than 50% of the nail or there is an associated fracture. A more recent conservative approach states that removal of the nail is best reserved for those injuries that damage the nail plate and surrounding tissues, regardless of the size of the hematoma or presence of a tuft fracture. In many cases, trephination of the nail is sufficient to relieve pain.

Clinical Pearls

1. Subungual hematomas are a sign of nail bed injury.

2. Subungual hematomas with surrounding nail bed and nail fold injuries require nail removal and evaluation of the nail bed for injury and careful repair if needed.

3. A hand-held, high-temperature, portable cautery device is a good tool for drainage of a subungual hematoma.

Compartment Syndrome

Associated Clinical Features

Compartment syndrome develops when the pressure in a closed or inelastic fascial space increases to a point where it causes compression and dysfunction of vascular and neural structures. The five "Ps" that characterize compartment syndrome are pain, pallor, paresthesias, increased pressure, and pulselessness.

The earliest symptom is severe pain out of proportion to the physical findings. The pain is worsened with passive stretching of muscle within the compartment. Anesthesia-paresthesia is an early sign of nerve compromise. Motor weakness and pulselessness are late signs. Causes include compression, exercise, circumferential burns, frostbite, constrictive dressings, arterial bleeding, soft tissue injury, and fracture. Locations where compartment syndrome can occur include the interossei of the hand, volar and dorsal compartments of the forearm (Fig. 11.46), the gluteus medius, and anterior, peroneal, and deep posterior compartments of the leg (Fig. 11.47). A creatine phosphokinase (CPK) of 1000 to 5000 U/mL may add to suspicion of the diagnosis. Myonecrosis (Fig. 11.48) can cause myoglobinuria and renal failure.

Figure 11.46

Compartment Syndrome A swollen and tense right forearm typical for the presentation of compartment syndrome. (Courtesy of Lawrence B. Stack, MD.)

Figure 11.47

Compartment Syndrome Anterior compartment syndrome of the left leg is manifested by anterior tibial pain, tense "woody" swelling, and erythema. Early in the course, passive plantarflexion may cause referred pain to the compartment. Later, the patient may develop foot drop. (Courtesy of Timothy Coakley, MD.)

Figure 11.48

Compartment Syndrome, Late Sequelae Muscle necrosis may result from compartment syndrome, as seen in this patient, who has undergone fasciotomy. (Courtesy of Kevin J. Knoop, MD, MS.)

Differential Diagnosis

Soft tissue swelling, deep venous thrombosis (DVT), neuropraxia, cellulitis, arterial intimal damage, snakebite, inflammation, or hematoma formation can be mistaken for a compartment syndrome.

Emergency Department Treatment and Disposition

The initial treatment is removal of any constrictive dressing and frequent evaluation. If there is no improvement or there are no constrictive dressings in place, decompression via a fasciotomy should be considered. Intracompartmental pressure monitoring (Fig. 11.49) should be performed to assess the need for immediate decompression. Pressures greater than 30 mmHg with signs and symptoms are suggestive of compartment syndrome, whereas pressures greater than 40 are diagnostic.

Figure 11.49

Compartment Pressures Intracompartmental pressure monitoring can be accomplished with commercially available devices. Normal tissue pressures should be less than 10 mmHg. (Courtesy of Selim Suner, MD, MS.)

Clinical Pearls

1. The diagnosis of compartment syndrome should be made early and be based on clinical evaluation and the mechanism of injury. Crush or compression injuries should heighten suspicion.

2. The most common areas of the extremities affected by compartment syndrome are the anterior compartment of the lower leg due to proximal tibial fractures and the volar compartment of the forearm secondary to fracture of the ulna or radius and supracondylar fracture.

3. If a compartment syndrome is suspected, the compartment pressure should be measured.

Hip Dislocations

Associated Clinical Features

Hip dislocations can be anterior, posterior, or central. Posterior hip dislocations are the most common, resulting from forces exerted on a flexed knee (e.g., a passenger in a motor vehicle accident whose knees hit the dashboard). The extremity is found shortened, internally rotated, and adducted (Fig. 11.50). Associated fractures occur commonly. Anterior hip dislocations occur when there is forced abduction to the femoral head, which forces the head out through a tear in the anterior capsule. Anterior dislocations can be superior (pubic) or inferior (obturator). The leg is abducted, externally rotated, and flexed with an inferior anterior hip dislocation. A superoanterior hip dislocation has the leg positioned in extension, slight abduction, and external rotation. Patients complain of severe hip pain and decreased range of motion.

Figure 11.50

Hip Dislocation Typical clinical appearance and patient position of a left posterior hip dislocation. Note internal rotation of the affected extremity (A). Radiograph of patient (B). (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Fractures of the femoral head, pelvis, femoral neck, acetabulum, and femoral shaft are sometimes mistaken for hip dislocations on initial examination.

Emergency Department Treatment and Disposition

Treatment for dislocations is early closed reduction using sedation, analgesia, and muscle relaxants. Anterior dislocations are reduced using strong in-line traction with the hip flexed and internally rotated, followed by abduction. Posterior dislocations are reduced using in-line traction with the hip flexed to 90 degrees, followed by gentle internal to external rotation. A neurovascular examination and radiographic evaluation should occur before and after any attempts at reduction. Orthopedic consultation should be obtained as early as possible. These patients require admission, with frequent neurovascular evaluation.

Clinical Pearls

1. Complications of posterior hip dislocations include sciatic nerve injury and avascular necrosis.

2. Immediate reduction is imperative. The longer the delay in reduction, the greater the incidence of avascular necrosis.

3. Patients with prosthetic joints are at greater risk for dislocation, which can occur after only slight trauma.

Hip Fracture

Associated Clinical Features

Fractures of the femoral head and femoral neck and intertrochanteric fractures are termed hip fractures. For classification, hip fractures are generally divided into intracapsular (femoral head and neck fractures) and extracapsular (trochanteric, intertrochanteric, and subtrochanteric fractures) (Fig. 11.51). Accurate classification is important because of the different prognosis associated with each group. Intracapsular fractures are more likely to be associated with disruption of the vascular supply and resultant avascular necrosis. On the other hand, extracapsular fractures rarely impair the vascular supply.

Figure 11.51

Hip Fractures This illustration depicts the different types of proximal femoral fractures.

All patients have complete immobility at the hip joint. Complaints include hip and groin pain, tenderness, and an inability to walk or place pressure on the affected side. There is shortening of the affected leg as well as abduction and external rotation (Fig. 11.52). Intertrochanteric fractures are associated with significant pain, a shortened extremity, marked external rotation, swelling, and ecchymosis around the hip (Fig. 11.53). Fractures of the femoral neck are suggested when the extremity is held in slight external rotation, abduction, and shortening. Dislocation of the hip is commonly associated with femoral head fractures. Patients with anterior dislocation and a femoral head fracture hold the lower extremity in abduction and external rotation. Patients with a posterior dislocation hold the extremity in adduction and internal rotation and display notable shortening.

Figure 11.52

Hip Fracture Patients with hip fractures often present with the affected extremity shortened, externally rotated, and abducted. Note the rotation and shortening in this patient with a right intertrochanteric fracture. (Courtesy of Cathleen M. Vossler, MD.)

Figure 11.53

Hip Fracture Radiographic examination reveals an intertrochanteric fracture. (Courtesy of Cathleen M. Vossler, MD.)

The femoral head has a tenuous vascular supply which includes three sources: the artery of the ligamentum teres, the metaphyseal arteries, and the capsular vessels. Any injury that disturbs the anatomy of the hip can lead to compromise of this vascular supply.

Shenton's line and the normal neck shaft angle of 120 to 130 degrees (obtained by measuring the angle of the intersection of lines drawn down the axis of the femoral shaft and the femoral neck) should be checked in all suspicious injuries.

Differential Diagnosis

Pelvic fracture, femoral shaft fracture, stress fracture, and hip dislocation are sometimes mistaken for a hip fracture prior to radiographic examination.

Emergency Department Treatment and Disposition

Once the patient is stabilized, the hip fracture is reduced via traction. Femoral head fracture-dislocations are an orthopedic emergency and require immediate reduction. A neurovascular examination should be carefully performed before and after any reduction attempts. Orthopedic consultation should be obtained early, since these patients will require admission and in most cases surgical reduction and fixation.

Clinical Pearls

1. Hip pain can be referred to other areas. Therefore, in any patient complaining of knee or thigh pain, consider the possibility of a hip fracture.

2. Fracture-dislocation of the femoral head requires great forces, and associated injuries such as chest, intraabdominal, and retroperitoneal injuries should be considered.

3. Intracapsular fractures usually have much less blood loss than extracapsular fractures because of hematoma containment within the capsule.

4. Fractures of the hip may be diagnosed by auscultation of differences in bone conduction between the patient's two extremities. This is performed by placing the stethoscope's diaphragm on the anterosuperior iliac spine and giving the patella several soft taps.

5. In the elderly, hip fractures are usually secondary to a fall. Be sure to address the cause of the fall to rule out a pathologic etiology (i.e., acute myocardial infarction, syncope, etc.).

Pelvic Fracture

Associated Clinical Features

Pelvic fractures range in severity from stable pubic rami fractures to unstable fractures with hemorrhagic shock. Pain is the most frequently encountered complaint. Blood at the urethral meatus, a high-riding prostate, gross hematuria, or a scrotal hematoma (Fig. 11.54) are all signs of associated urinary tract injury. Ecchymosis of the anterior abdominal wall, flank, sacral, or gluteal region should be regarded as a sign of serious hemorrhage. Blood found during rectal examination may indicate puncture of the wall of the rectum from a pelvic fracture. Leg shortening may also be seen. A careful neurologic examination is necessary, since there may be compromise of the sciatic, femoral, obturator, or pudendal nerves.

Figure 11.54

Pelvic Fracture Pelvic fractures may require emergent external fixation to help control hemorrhage. Scrotal hematoma, or Destot's sign, suggests a pelvic fracture. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Femoral fracture, hip fracture, or intraabdominal or retroperitoneal pathology (including hemorrhage, perforated viscus) can be confused with pelvic fractures.

Emergency Department Treatment and Disposition

Management includes initial stabilization and evaluation for any life-threatening injuries. Patients may require multiple large-bore IVs and type and crossmatch with blood readily available. Hemorrhagic shock occurs secondary to bleeding from a pelvic fracture and is the major cause of death in these patients. Retroperitoneal bleeding is unavoidable and up to 6 L of blood can easily be lost. Early orthopedic consultation is critical for emergent external fixation. Angiography should be performed to control small bleeding sites if there is continued exsanguination.

Clinical Pearls

1. MAST (medical antishock trousers) may be used to temporarily stabilize pelvic fractures.

2. Don't assume that a pelvic fracture is the sole cause of hemorrhagic shock in a patient. Look for other sources.

3. Posterior pelvic fractures are more likely to result in hemorrhage and neurovascular damage. Anterior pelvic fractures are more likely to cause urogenital damage.

4. Urinary tract injury is highly associated with pelvic fracture and must be ruled out. If there are any signs of genitourinary injury, a Foley catheter should not be placed until a retrograde urethrogram has been performed.

5. Displacement of pelvic ring fractures is usually associated with fracture or dislocation of another ring element (Fig. 11.55).

Figure 11.55

Pelvic Fracture Radiographic examination reveals bilateral sacroiliac joint diastasis, complete transverse fracture of the sacrum, and comminuted fractures of the right superior and inferior pubic rami. (Courtesy of Cathleen M. Vossler, MD.)

Femur Fracture

Associated Clinical Features

Femoral fractures occur secondary to great forces, like those associated with motor vehicle accidents. The diagnosis is usually evident on visualization of the thigh (Fig. 11.56) and confirmed radiographically (Fig. 11.57). The position of the leg can help determine at which point the femur is fractured. Commonly associated injuries include hip fracture and dislocation as well as ligamentous injury to the knee. Hematoma formation is common.

Figure 11.56

Femur Fracture A closed midshaft femoral fracture. Note the deformity in the middle of the thigh, consistent with this injury. (Courtesy of Daniel L. Savitt, MD.)

Figure 11.57

Femur Fracture Radiographic examination reveals a comminuted displaced distal femoral fracture. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Pelvic fracture, hematoma, hip fracture, hip dislocation, and contusion can be mistaken for femoral fracture prior to radiographic examination.

Emergency Department Treatment and Disposition

Initial management includes stabilization and evaluation for any life-threatening injuries. It is important to keep in mind that a large amount of blood loss can occur (average blood loss for a femoral shaft fracture is 1000 mL). These patients should have two large-bore intravenous lines and be crossmatched for blood products should they become necessary. The extremity should be immobilized and splinted with a traction device such as a Hare splint. Once this is accomplished, radiographic evaluation of the extremity should be performed. Orthopedic consultation should be obtained and admission arranged. The majority of intertrochanteric and subtrochanteric fractures require operative fixation and stabilization. An open fracture is an orthopedic emergency; these patients require tetanus prophylaxis, antibiotic coverage, and emergent irrigation and debridement in the operating room.

Clinical Pearls

1. Pain can be referred. Any injury between the lumbosacral spine and the knee can be referred to the thigh or knee.

2. Vascular compromise can occur and should be suspected with an expanding hematoma, absent or diminished pulses, or progressive neurologic signs. Neurovascular status needs to be assessed frequently.

3. Femoral shaft fractures can mask the clinical findings of a hip dislocation; thus radiographs of the pelvis and hips should be obtained routinely.

Knee Extensor Injuries

Associated Clinical Features

The quadriceps and its associated tendons predominantly extend the knee. This mechanism may be disrupted by quadriceps or patellar tendon rupture or patellar fracture. Collagen disorders, degenerative disease, tendon calcifications, and fatty tendon degeneration may predispose to these problems.

Quadriceps tendon ruptures are more common than patellar tendon ruptures and are more often seen in the elderly. Forced flexion during quadriceps contraction (as in a fall from a curb) may cause sudden buckling and pain. The patella is inferiorly displaced with proximal ecchymosis and swelling. A soft tissue defect at the distal aspect of the quadriceps may be apparent on examination (Fig. 11.58). Proximal displacement of the patella with inferior pole tenderness and swelling suggest a patellar tendon rupture (Fig. 11.59). Lateral radiographs help distinguish between the two (Fig. 11.60).

Figure 11.58

Quadriceps Tendon Rupture Inferior displacement of the patella and a distal quadriceps defect suggest quadriceps tendon rupture. (Courtesy of Robert Trieff, MD.)

Figure 11.59

Patellar Tendon Rupture Proximal displacement of the patella and inferior pole tenderness may be subtle, as in this patient with left patellar tendon rupture. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.60

Patellar Tendon Rupture A lateral radiograph of the patient in Fig. 11.59 reveals the proximal patellar displacement seen with complete patellar tendon rupture. (Courtesy of Kevin J. Knoop, MD, MS.)

Patellar fractures may be transverse, stellate, or vertical. They may be caused by direct trauma or through avulsion secondary to the quadriceps pull against resistance. Tenderness, swelling, and sometimes a palpable defect are present.

Differential Diagnosis

Knee dislocation, patellar contusion, or proximal femoral fracture may be confused with knee extensor mechanism injuries.

Emergency Department Treatment and Disposition

An optimal outcome for quadriceps or patellar tendon rupture is realized with early consultation, immobilization, and consideration of operative repair. There are nonsurgical advocates who recommend conservative treatment.

Nondisplaced transverse patellar fractures should be treated with long-leg splinting in full extension and referral to orthopedics. Patients with displaced patellar fractures generally receive operative treatment or excision of the patella.

Clinical Pearls

1. Patients with complete ruptures have loss of active extension of the knee.

2. Avulsion of the tibial tuberosity may also show a hide-riding patella on physical and radiographic examination.

3. Magnetic resonance imaging may distinguish partial from complete tears.

4. Patellar fractures may be complicated by future degenerative arthritis or focal avascular necrosis.

Patellar Dislocations

Associated Clinical Features

Patellar dislocations result from direct trauma to the patella. A force is applied to the upper portion of the patella at the same time as a rotational force affects the knee. The most common dislocations are lateral, but horizontal, superior, and intercondylar dislocations also occur. These tend to be recurrent owing to the resultant increased laxity of the supporting structures. Patients who have had recurrent dislocations often reduce the dislocation prior to arrival at the ED. Common complaints include pain, swelling, and a deformity in the knee. Physical examination reveals fullness or deformity in the lateral aspect of the knee (Fig. 11.61). Fractures of the patella or femoral condyle occur in 5% of patients.

Figure 11.61

Patellar Dislocation This photograph depicts a lateral patellar dislocation of the right knee. Note the obvious lateral deformity of the right patella. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Distal femoral fracture, quadriceps rupture, patellar tendon rupture, patellar fracture, or knee dislocation can be mistaken for a patellar dislocation.

Emergency Department Treatment and Disposition

Reduction is easily accomplished and results in immediate relief of pain. Lateral dislocations are reduced by flexing the hip, extending the knee, and gently directing pressure medially on the patella. Other dislocations generally require open reduction. Radiographic examination should be obtained to document patellar position as well as evaluate for fracture. These patients require a knee immobilizer or long leg cast in full extension for 4 to 6 weeks. Orthopedic consultation should be obtained, since these patients require further evaluation.

Clinical Pearls

1. A dislocated patella may reduce spontaneously prior to presentation and should be addressed as a possibility in any patient who presents with knee pain. This may be elucidated by inquiring about a knee deformity at the time of injury that is no longer present.

2. Complications of patellar dislocation include degenerative arthritis, recurrent dislocations, and fractures.

3. The patellar apprehension test should be performed on these patients: patients have the sensation that the patella will dislocate when there is lateral pressure placed on the patella, at which point they grab for their knee.

Knee Dislocation

Associated Clinical Features

The peak incidence of knee dislocation is in the third decade of life. It is more common in males. Knee dislocations are classified by the direction of tibial displacement relative to the femur. They may be anterior (Fig. 11.62), posterior (Fig. 11.63), medial, lateral, or rotary. Anterior dislocations account for 50 to 60% of dislocations and usually occur after high-energy hyperextension injuries. Two-thirds of all knee dislocations are secondary to motor vehicle crashes, with the remainder from falls, from sports, and from industrial injuries. Anterior dislocations are associated with a high incidence of associated popliteal artery and peroneal nerve injuries. The affected limb will have gross deformity around the knee with swelling and immobility; peroneal nerve injury manifests itself with decreased sensation at the first web space with impaired dorsiflexion of the foot. Many of these dislocations will reduce spontaneously prior to arrival in the ED.

Figure 11.62

Anterior Knee Dislocation A radiograph demonstrating anterior displacement of the tibia in relation to the femur. (Courtesy of Selim Suner, MD, MS.)

Figure 11.63

Posterior Knee Dislocation A clinical photograph demonstrating posterior displacement of the tibia in relation to the femur. (Courtesy of Paul R. Sierzenski, MD.)

Differential Diagnosis

Tibia/fibular fractures, knee fractures, femoral fractures, or patellar dislocation may mimic knee dislocation.

Emergency Department Treatment and Disposition

Emergent treatment includes early reduction, immobilization, assessment of distal neurovascular function, and emergent orthopedic referral. The knee should be evaluated for valgus and varus stability at 20 degrees flexion. Reduction of anterior dislocation is accomplished by having an assistant apply longitudinal traction on the leg while keeping one hand on the tibia and simultaneously lifting the femur anteriorly back into position. A posterior splint with the knee in 15 degrees of flexion is used for immobilization and to avoid tension on the popliteal artery. The patient should be admitted for observation and arteriography. Historically, arteriography was advocated for all anterior knee dislocations even with a normal postreduction vascular examination; however, low-energy knee dislocations with normal postreduction vascular examinations may not require arteriography and can be followed by serial examination. Duplex Doppler ultrasonography has been advocated by some authors and correlates well with arteriography but may miss intimal tears.

Clinical Pearls

1. Knee dislocations are often associated with a fracture of the proximal tibia.

2. The presence of distal pulses in the foot does not rule out an arterial injury; there is a 10% incidence of popliteal injury despite present distal pulses.

3. Vascular repair after 8 h of injury carries an amputation rate of greater than 80%.

Tib-Fib Fractures

Associated Clinical Features

The tibia sustains a high frequency of fractures secondary to direct trauma because of its subcutaneous location. Tibial fractures may be complicated by nonunion, neurovascular injury, or compartment syndrome. Suspect tibial fractures with trauma to the lower extremity, pain, and inability to bear weight. Tibial diaphyseal fractures carry a high risk for compartment syndrome, and distal neurovascular status should always be documented.

Fibular fractures may be isolated or be associated with injuries of the tibia (Fig. 11.64). Isolated fibular fractures are caused by direct trauma to the lateral aspect of the leg. Contrary to tibial fractures, complications of isolated fibular fractures are rare. The fibula is a non-weight-bearing structure, so isolated fractures are anatomically splinted by an intact tibia. Distal fibular fractures may include a disrupted ankle joint, as evidenced by a widened or nonuniform mortise on the AP radiograph.

Figure 11.64

Tib-Fib Fracture Deformity associated with a midshaft tibial and fibular fracture. (Courtesy of Kevin J. Knoop, MD, MS.)

The Maisonneuve fracture is a combination of an oblique proximal fibular fracture, disruption of the interosseous membrane and tibiofibular ligament distally, and a medial malleolar fracture or tear of the deltoid ligament. This fracture occurs when an external rotational force is applied to the foot, producing a fracture of the proximal third of the fibula. Physical examination findings include tenderness at the anteromedial ankle joint capsule or at the ankle syndesmosis in combination with proximal fibular tenderness.

Differential Diagnosis

Contusion, disseminated vascular coagulation, compartment syndrome, and sprains must be considered.

Emergency Department Treatment and Disposition

Treatment of tibial fractures depends on whether they are open or closed and on the degree of displacement. All open fractures require immediate orthopedic referral for surgical treatment and reduction. Closed fractures that cannot be reduced may also need open reduction. Patients with isolated nondisplaced tibial fractures may be splinted, started on ice therapy, and referred for outpatient treatment. Treatment of fibular fractures is dictated by the degree of pain experienced by the patient and the involvement of the ankle joint. Nondisplaced fractures can be treated with an air cast, while those with displacement should be place in a sugar-tong splint and referred for short-term orthopedic evaluation. Treatment of a Maisonneuve fracture depends on the status of the ankle mortise. An intact mortise with no joint space widening can be treated by casting. A mortise not in anatomic alignment requires open reduction.

Clinical Pearls

1. Early follow up is required for all tibial fractures owing to the risk of compartment syndrome.

2. The peroneal nerve crosses over the head of the fibula and is subject to injury with a Maisonneuve fracture.

3. Some patients with Maisonneuve fracture may complain only of ankle pain. Maisonneuve fracture represents about 1 in 20 ankle fractures, so always examine the proximal fibula in patients complaining of ankle pain.

Fracture Blisters

Associated Clinical Features

Fracture blisters are vesicles or bullae that arise secondary to swelling from soft tissue injury and fracture formation (Fig. 11.65). The most commonly affected areas include the tibia, ankle, and elbow. Patients note blister formation within 1 to 2 days after the initial trauma. Patients complain of pain, swelling, ecchymosis, and decreased range of motion. Complications include infection, deep venous thrombosis, and compartment syndrome.

Figure 11.65

Fracture Blisters Fracture blisters in a patient who fell down four steps on the evening prior to presentation. The patient had initially complained of ankle pain, decreased range of motion, and an inability to bear weight. Upon awakening the next morning, he noted ecchymosis, swelling, and blister formation. Radiographics revealed fracture of the fibula. (Courtesy of Daniel L. Savitt, MD.)

Differential Diagnosis

Sprain, fracture, cellulitis, necrotizing fasciitis, compartment syndrome, or burns can be mistaken for fracture blisters.

Emergency Department Treatment and Disposition

Blisters are generally left intact, and the underlying fracture is treated.

Clinical Pearls

1. Blisters can be seen with other conditions, including barbiturate overdose; in the setting of trauma, however, they frequently indicate an underlying fracture.

2. Blisters are managed in a similar fashion to second-degree burns.

Achilles Tendon Rupture

Associated Clinical Features

Rupture of the Achilles tendon occurs most frequently in middle-aged males involved in athletic activities. Three mechanisms result in this injury: a direct blow to the tendon, forceful dorsiflexion of the ankle, or increased tension on an already taut tendon. Rupture occurs 2 to 3 cm above the tendon's attachment to the calcaneus (Fig. 11.66). Patients complain of a feeling of being hit in the posterior aspect of the lower leg. They may hear or feel a pop. There is weakness when pushing off of the foot; pain, edema, and ecchymosis develop. Thompson's test can be diagnostic of an Achilles rupture (Fig. 11.67). The patient should be placed in a prone position; the gastrocnemius muscle should be grasped and squeezed. If the Achilles tendon is even partially intact, then the foot will plantarflex; if ruptured, there will be no movement of the foot.

Figure 11.66

Achilles Tendon Rupture This photograph depicts a patient with a right Achilles tendon rupture. Note the loss of the normal resting plantarflexion on the right owing to disruption of the tendon. This is seen with the patient in a nonweight-bearing position. Swelling is also apparent over the site of the tendon injury. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.67

Thompson's Test This illustration demonstrates the Thompson's test, where compression of the gastrocnemius-soleus complex normally produces plantarflexion of the foot (1). If the tendon is completely ruptured, this will not occur (2).

Differential Diagnosis

Partial Achilles tendon tear, plantaris tendon rupture, ankle sprain, Achilles tendinitis, and partial gastrocnemius muscle rupture have been confused with an Achilles tendon rupture.

Emergency Department Treatment and Disposition

Treatment is either operative or conservative. In either case, the extremity is immobilized without weight bearing for 6 weeks, followed by 6 weeks of partial weight bearing. ED treatment consists of elevation, analgesia, ice, and immobilization with a posterior splint. Orthopedic consultation should be obtained so that a plan of treatment can be chosen. These patients can be discharged home with close orthopedic follow-up or can be admitted for acute repair. Partial tears are generally treated conservatively.

Clinical Pearls

1. Advantages to surgical repair are increased strength and mobility and a decreased rate of rerupture.

2. Approximately 25% of these injuries are initially misdiagnosed as ankle sprains.

3. These patients maintain the ability to plantarflex the foot in a non-weight-bearing position owing to the action of the tibialis posterior, toe flexor, and peroneal muscles.

4. Palpation of the tendon alone may not detect rupture, as the tendon sheath is often intact.

Ankle Dislocation

Associated Clinical Features

Ankle dislocations require forces of great magnitude. Posterior and lateral dislocations are the most common, but the ankle can also dislocate medially, superiorly, or anteriorly (Figs. 11.68, 11.69, 11.70). A posteriorly dislocated ankle is locked in plantarflexion with the anterior tibia easily palpable. The foot has a shortened appearance, with the ankle very edematous. Anterior dislocations present with the foot dorsiflexed and elongated. Lateral dislocations present with the entire foot displaced laterally. Ankle dislocations are commonly associated with malleolar fractures.

Figure 11.68

Posterior Ankle Dislocation A posterior ankle dislocation is pictured. Radiographs showed an associated fracture. (Courtesy of Mark Madenwald, MD.)

Figure 11.69

Ankle Dislocations This illustration depicts different types of ankle dislocations. Arrows denote direction of the injury force. (Adapted with permission from Simon R: Emergency Orthopedics: The Extremities. New York: Appleton & Lange, 1987, p. 402.)

Figure 11.70

Lateral Ankle Dislocation The foot is laterally displaced in this patient with a lateral ankle dislocation. A radiograph revealed fracture of the distal fibula. (Courtesy of Cathleen M. Vossler, MD.)

Differential Diagnosis

Fractures of the tibia, fibula, or talus, as well as ankle sprains, are all commonly mistaken for an ankle dislocation on initial examination. A subtalar foot dislocation (Fig. 11.71) resembles ankle dislocation.

Figure 11.71

Subtalar Dislocation This patient landed on his foot while playing basketball. Neurovascular status was intact, and the ankle was promptly reduced after x-ray showed no associated fracture. (Courtesy of Kevin J. Knoop, MD, MS.)

Emergency Department Treatment and Disposition

Routine radiographs should be obtained to identify any fractures. Reduction should occur before radiography if circulatory compromise exists. To reduce the ankle, gentle traction is applied to the foot, in an opposite direction of the force that caused the injury. Neurovascular status should be checked before and after any attempts at reduction or immobilization. Reduction usually requires conscious sedation, a Bier block, or general anesthesia. Patients should be placed in a posterior splint with immediate referral to an orthopedic surgeon for hospitalization.

Clinical Pearls

1. These injuries are commonly associated with malleolar fractures and often require open reduction and internal fixation.

2. Fifty percent of ankle dislocations are open and require surgical debridement.

3. There is an increased incidence of avascular necrosis following ankle dislocation.

Calcaneus Fracture

Associated Clinical Features

The calcaneus is the most frequently fractured tarsal bone. Injuries are associated with falls from a height or twisting mechanisms. There are two types: intra- and extraarticular. Intraarticular fractures generally result from an axial load. These patients have severe heel pain in association with soft tissue swelling and ecchymosis of the pericalcaneal tissues extending to the arch. Heel contour can be distorted. Extraarticular fractures are less common and may occur secondary to twisting or avulsive muscle forces. They are divided anatomically into the following types: anterior process, tuberosity (beak or avulsion), medial process, sustentaculum tali, and body.

Differential Diagnosis

Lisfranc's fracture, midfoot or forefoot fracture, and ankle sprain must be considered.

Emergency Department Treatment and Disposition

Differentiate extraarticular (25 to 35%) fractures, which have a good prognosis, from intraarticular (70 to 75%) fractures. Oblique radiographs and computed tomography (CT) scans can be used to rule out involvement of the subtalar joint. With intraarticular fractures, a lateral foot radiograph reveals a reduction in Bohler's angle (Figs. 11.72, 11.73), the posterior angle formed by intersection of a line from posterior to middle facet and a line from anterior to middle facet. Bohler's angle is normally between 28 and 40 degrees, with an average of 30 to 35. Angles of less than 28 degrees, or more than 5 degrees less than the uninjured side, suggest a fracture. Intraarticular fractures require urgent orthopedic consultation, since open reduction and internal fixation are usually necessary.

Figure 11.72

Bohler's Angle Bohler's angle is formed by the intersection of lines drawn tangentially to the anterior (A) and posterior (B) elements of the superior surface of the calcaneus (C). A normal angle is between 28 and 40 degrees. Angles of less than 28 degrees are suggestive of a calcaneal fracture.

Figure 11.73

Calcaneal Fracture This patient fell from a ladder and struck his heel. A cortical step-off is seen on the inferior aspect of the calcaneus. Bohler's angle has been calculated at approximately 22 degrees. (Courtesy of Alan B. Storrow, MD.)

Nondisplaced extraarticular fractures not involving the subtalar joint generally heal well with bulky compressive dressings, rest, ice, elevation, and non-weight bearing for the first 6 weeks. However, some may require open reduction; therefore orthopedic referral is necessary.

Clinical Pearls

1. Calcaneal fracture warrants a diligent search for associated injuries. 20% of calcaneal fractures are associated with spinal fractures, 7% have contralateral calcaneal fractures, and 10% are associated with compartment syndromes. The subtalar joint is disrupted in 50% of cases. A high index of suspicion for thoracic aortic rupture and renal vascular pedicle disruption must be maintained when calcaneal fractures are seen.

2. Minimally displaced fractures of the anterior process are easily missed and should be suspected in a patient who does not recover appropriately from a lateral ankle sprain. If the fragment is small or diagnosis is delayed, this fragment can simply be excised.

3. CT scanning is the optimal imaging technique.

Ankle Sprain

Associated Clinical Features

Ankle sprains are extremely common problems in the ED. Classification of these injuries based on physical examination and radiography helps guide management and definitive treatment.

The most common mechanism is an inversion stress that injures, in order, the joint capsule, anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament. Since the medial deltoid ligament is quite strong and elastic, serious eversion injuries usually result in avulsion of the medial malleolus or fracture of the lateral malleolus.

A first-degree sprain is defined by a stretch injury, or microscopic damage, to ligaments resulting in pain, tenderness, minimal swelling, and maintenance of the ability to bear weight. A second-degree sprain is defined by a partial tear of the ligamentous structures resulting in pain, swelling (Fig. 11.74), local hemorrhage (Fig. 11.75), and moderate degree of functional loss. A third-degree sprain is a complete tear of the ligament or ligaments and presents with positive stress testing, significant swelling, and an inability to bear weight.

Figure 11.74

Ankle Sprain Comparison view of a patient with a second-degree left lateral ankle sprain. Note the swelling and asymmetry of the affected area. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.75

Ankle Sprain Note the dependent ecchymosis and swelling in this patient with a second-degree left lateral ankle sprain. (Courtesy of Lawrence B. Stack, MD.)

Differential Diagnosis

Malleolar and fifth metatarsal fractures can be confused with ankle sprains prior to radiographs. Any patient with joint pain should have an infectious etiology considered.

Emergency Department Treatment and Disposition

First-degree injuries are treated with ice packs, elevation, woven elastic (Ace) wrap, and early mobilization. For patients with mild second-degree sprains, immobilization for 72 h followed by use of an ankle support has been advocated. More serious second-degree and all third-degree sprains should receive immobilization, ice, and elevation and be referred to orthopedics. In younger patients, surgery is an option, although clear recommendations are lacking.

Clinical Pearls

1. Ankle injuries are the most common orthopedic problem in emergency medicine.

2. Complications of ankle sprains include instability, persistent pain, recurrent sprains, and peroneal tendon dislocation.

3. Published guidelines known as the Ottawa Ankle Rules were designed to limit unnecessary radiographs by clinical scoring.

4. The most common eversion injury is a fracture of the lateral malleolus. Since inversion injuries also produce lateral problems, the most common injuries to the ankle involve the lateral side.

5. Both malleoli, the proximal fibula, and the fifth metatarsal should be examined for injury in evaluating a patient with an ankle sprain.

Fractures of the Fifth Metatarsal Base

Associated Clinical Features

Patients complain of pain, swelling, decreased range of motion, and tenderness over the lateral aspect of the foot (Fig. 11.76). Fractures of the fifth metatarsal base have been generically referred to as Jones fractures. However, the fractures can be divided into three types, depending on their anatomic location. Treatment is determined by this division.

Figure 11.76

Jones Fracture This patient sustained an injury of the fifth metatarsal and presented with pain and swelling over this site. His radiograph revealed a fracture. (Courtesy of Cathleen M. Vossler, MD.)

The classic Jones fracture is a transverse fracture of the fifth metatarsal diaphysis (Figs. 11.77, 11.78). It occurs when a force is applied to a plantarflexed and inverted foot. It is also referred to as a stress fracture of the proximal shaft and is usually due to repetitive stress injury. Patients often have prodromal symptoms.

Figure 11.77

Fifth Metatarsal Base Fractures This illustration depicts an avulsion fracture (A) and a classic Jones fracture (B).

Figure 11.78

Jones Fracture Radiograph with typical appearance for a diaphyseal fracture of the fifth metatarsal base. (Courtesy of Alan B. Storrow, MD.)

A fracture at the metaphyseal–diaphyseal junction has been termed a pseudo-Jones fracture. It is always an acute injury.

The last type is an avulsion fracture of the fifth metatarsal base caused by sudden inversion of the foot (Figs. 11.77, 11.79). The avulsion injury is caused by traction on the lateral cord of the plantar aponeurosis.

Figure 11.79

Fifth Metatarsal Avulsion Fracture Radiograph illustrating an avulsion-type fracture of the fifth metatarsal base, sometimes referred to as a ballet dancer's fracture (see Fig. 11.77). (Courtesy of Alan B. Storrow, MD.)

Differential Diagnosis

Care must be taken to avoid confusing the two sesamoid bones in this area with a fracture. The more common of the two, the os peroneum (present in approximately 15%), lies within the peroneus longus tendon. More rare is the os vesalianum, which lies in the peroneus brevis tendon. Both have smooth, rounded surfaces and usually occur bilaterally. The apophysis of the fifth metatarsal base can also be mistaken for a fracture. It usually fuses by 16 years of age, although some fail to fuse.

Other entities to consider include ankle sprain, other metatarsal fractures, and foot dislocations.

Emergency Department Treatment and Disposition

A Jones fracture should be splinted and referred to orthopedics for definitive repair. It may heal slowly and cause permanent pain and disability. Surgical treatment is sometimes recommended, particularly since the stress involved with these fractures usually occurs in the sporting activities of young patients.

A pseudo-Jones fracture usually heals without complication, although more slowly than the avulsion fracture. Referral to orthopedics for a walking or non-weight-bearing cast, according to local preference, is indicated.

The avulsion fracture usually heals rapidly and seldom leads to permanent disability. Most orthopedic physicians treat these patients symptomatically with a short leg walking cast or hard-sole shoe for 2 to 3 weeks. Surgery is rarely indicated.

Clinical Pearls

1. It is important to differentiate between the different types of fractures of the fifth metatarsal base; treatment and disposition are dictated by these categories.

2. The original description of these fractures was by Sir Robert Jones, who personally sustained an injury while dancing. The avulsion fracture is sometimes referred to as the ballet dancer's fracture.

3. The classic Jones fracture has a high incidence of delayed healing and nonunion.

Lisfranc's Fracture-Dislocation

Associated Clinical Features

This is the most commonly misdiagnosed foot injury. The Lisfranc joint (tarsometatarsal joint) connects the midfoot and forefoot. It is defined by the articulation of the bases of the first three metatarsals with the cuneiforms and the fourth and fifth metatarsals with the cuboid. Lisfranc's ligament anchors the second metatarsal base to the medial cuneiform. Although disruption of the Lisfranc joint is typically associated with high-energy mechanisms—such as falls, vehicle crashes, and direct crush injuries—they also occur with lower-intensity mechanisms. Although the clinical presentation is variable, severe midfoot pain and the inability to bear weight are usually present (Fig. 11.80). Radiographs may reveal displacement of the metatarsals in one direction (homolateral) or a split, usually between the first and second metatarsals (divergent) (Figs. 11.81, 11.82).

Figure 11.80

Lisfranc Fracture-Dislocation This patient presented with extreme midfoot pain and swelling. (Courtesy of Kevin J. Knoop, MD, MS.)

Figure 11.81

Lisfranc Fracture-Dislocations Homolateral (left) and divergent (right) Lisfranc fracture-dislocations.

Figure 11.82

Lisfranc Fracture-Dislocation A divergent Lisfranc fracture-dislocation. Note the disruption of the alignment of the second metatarsal and the middle cuneiform. Sometimes these injuries are not as apparent and comparison radiographs are necessary. (Courtesy of Alan B. Storrow, MD.)

Differential Diagnosis

Metatarsal fracture, navicular fracture, and contusion should be considered.

Emergency Department Treatment and Disposition

Meticulous evaluation of foot radiographs is key to diagnosis. The medial aspect of the first three metatarsals should align with the medial borders of the first three cuneiforms. The metatarsals should be aligned dorsally with their respective tarsal bones on the lateral view. The medial aspect of the fourth metatarsal should align with the medial cuboid. A disruption of these anatomic relationships is suggestive of a Lisfranc injury. Also suggestive are fractures or dislocations of the cuneiform or navicular and widening of the spaces between the first and second and second and third metatarsals. Lisfranc injuries warrant orthopedic evaluation in the ED. Closed reduction can be attempted using finger traps on the toes and placing traction on the hindfoot. Postreduction displacement of more than 2 mm or a tarsometatarsal angle of greater than 15 degrees requires surgical fixation. Tenderness over the Lisfranc complex with normal radiographs can reflect a strain of the complex. Stress (weight-bearing) radiographs may unmask joint instability. Lisfranc sprains should be placed in a short-leg walking cast. Potential complications include compartment syndrome, chronic pain, loss of the metatarsal arch, reflex sympathetic dystrophy, and biomechanical difficulties.

Clinical Pearls

1. Early recognition of Lisfranc fracture-dislocations is facilitated by assessing for the normal bony alignment on x-ray and by searching for frequently associated fractures.

2. Fractures of the second metatarsal base are considered pathognomonic of a Lisfranc injury.

Electrical Injury

Associated Clinical Features

Electricity may cause harm by heat generated through tissue resistance or directly by the current on cells. Skin, nerves, vessels, and muscles usually sustain the greatest damage. Many factors affect the severity of injury: type of current (DC or AC), current intensity, contact duration, tissue resistance, and current pathway through the body. Those at high risk for electrical injury are toddlers, those who perform risk-taking behavior, and people who work with electricity.

When electricity is deposited in the tissues, it may cause a host of injuries: contact burns (entry and exit—Fig. 11.83), thermal heating, arc burns, prolonged muscular tetany, or blunt trauma. Sudden death (asystole, respiratory arrest, ventricular fibrillation), myocardial damage, cerebral edema, neuropathies, disseminated intravascular coagulation, myoglobinuria, compartment syndrome, and various metabolic disorders have been described.

Figure 11.83

Electrical Injury This electrical worker grabbed a high-voltage power line with his hand and sustained an electrical injury. Exit wounds may occur where the patient is grounded, often through the feet when standing. Since this is a transthoracic injury, particular attention should be paid to cardiac monitoring. (Courtesy of Alan B. Storrow, MD.)

High-voltage DC or AC current typically causes a single violent muscular contraction that throws the victim from the source. As a result, blunt trauma and blast injuries may occur. Low-voltage AC currents (as from a household outlet) typically cause muscular tetany, forcing the victim to continue contact with the source.

Differential Diagnosis

Stroke, toxic ingestion, envenomation, myocardial infarction, assault, and seizures may mimic electrical injury.

Emergency Department Treatment and Disposition

After initial stabilization, consider cervical spine immobilization, oxygen administration, cardiac monitoring, and intravenous crystalloid infusion. A Foley catheter will help monitor urine output and is especially important if rhabdomyolysis is suspected.

Diagnostic testing to consider includes: ECG, CBC, urinalysis, CPK, CPK-MB, electrolytes, BUN, creatinine, and coagulation profile. Radiographic assessment is important for those with a suspicion of trauma.

Severe or high-risk injuries should be admitted to a burn or trauma center with surgical consultation. Patients with minor, brief, low-intensity exposures, with a normal ECG, normal urinalysis, and no significant burns or trauma may be considered for discharge after 6 to 8 h of observation.

Clinical Pearls

1. The low resistance of water makes its association with electricity particularly dangerous.

2. High-risk features include high-voltage exposure (>600 V), deep burns, neurologic injury, dysrhythmias, an abnormal electrocardiogram, evidence of rhabdomyolysis, suicidal intent, or significant associated trauma.

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