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CHAPTER 270: Elbow and Forearm Injuries 1809 FIGURE 269-22. Radial styloid fracture with lunate dislocation. PA = posteroanterior. [Photos contributed by Brooke Beckett, MD, Department of Radiology, Oregon Health & Science University, Portland, OR.] Oblique LateralP AAB C open reduction and internal fixation. Displacement of as little as 3 mm is often associated with accompanying scapholunate dissociation. Failure to recognize intercarpal ligament tears adds to the potential for subsequent posttraumatic arthritis. Refer to an orthopedist. In the ED, place a short arm splint positioning the wrist in mild flexion and ulnar deviation.  ULNAR STYLOID FRACTURE A forced radial deviation, dorsiflexion, or rotatory stress can fracture the ulnar styloid. The ulnar styloid fracture may be isolated or may accompany other injuries, such as a Colles’ fracture. Clinically, avulsion fractures are rarely significant, with the major consideration being the associated radial soft tissue and bony injuries. Displaced ulnar base fractures can be intra-articular and be associated with tears of the triangular fibrocartilage complex, which is the main stabilizer of the distal radioulnar joint. Patients complain of a painful clicking or locking sensation in the wrist. If the distal radioulnar joint is stable, ulnar styloid fractures are treated acutely in an ulnar gutter splint in slight ulnar deviation and neutral positioning of the wrist. If there is any question about stability, these patients should be referred acutely for surgical evaluation. Arthrograms or MRI imaging may be necessary to delineate the full extent of injury.  DISTAL RADIOULNAR JOINT DISRUPTION Distal radioulnar joint disruption is associated with several conditions including ulnar styloid and distal ulna fractures, triangular fibrocar tilage complex tear, ulnar impaction syndrome, Essex-Lopresti injury, and Galeazzi’s fracture. 4 The primary stabilizers of the distal radioulnar joint include the volar and dorsal radioulnar ligaments and triangular fibrocartilage complex. Disruption of the triangular fibrocartilage com plex of the distal radioulnar joint is generally seen with intra-articular or distal radial shaft fractures ( Galeazzi’s fracture-dislocation) 58 or with fractures of both bones of the forearm. Injury to the triangular fibrocartilage complex of the distal radioulnar joint is found in up to 84% of distal radius fractures. 4,53 These more apparent injuries often overshadow distal radioulnar joint disruption and, unfortunately, may remain unrecognized until subsequent pain and diminished wrist movement are appreciated. Isolated radioulnar joint dislocations are uncommon and are often unrecognized acutely, although these may occur in isolation in the set ting of distal ulnar dislocation. 4,53 Dorsal dislocation of the ulna results most often from falls on the wrist in hyperpronation and is associated with pain with supination on examination. The rare volar dislocation results from forced hypersupination of the wrist and is associated with pronation on examination. Patients with disruption of the distal radio ulnar joint present with pain at the distal radioulnar joint, weak grip, and restricted range of motion, especially pronation and supination. The ulnar head is often prominent but may be subtle and easily overlooked.

the wrist and is associated with pronation on examination. Patients with disruption of the distal radio ulnar joint present with pain at the distal radioulnar joint, weak grip, and restricted range of motion, especially pronation and supination. The ulnar head is often prominent but may be subtle and easily overlooked. A positive fovea sign has a sensitivity of 95% and specificity of 87% for triangular fibrocartilage complex instability, which is comprised of tenderness in the soft area between the ulnar styloid and flexor carpi ulnaris tendon. Signs of distal radioulnar joint instability include ulnar styloid fracture involving the base with ≥2 mm displacement, radius sigmoid notch fracture, wide distal radioulnar joint displacement, shortened radius, or failure to reduce distal radioulnar joint dislocation. 4,53 The posteroanterior radiograph reveals narrowing and overlap of the distal radioulnar joint. The lateral radiograph demonstrates either volar or dorsal displacement of the ulna, which is normally centered and overlapping the radius. Because slight oblique positioning of the wrist can produce a misleading appearance of ulnar displacement, make sure to obtain a properly positioned lateral view. A true lateral view should have superimposition of the four ulnar metacarpals, superimposition of the proximal pole of the scaphoid with the lunate and triquetrum, and the radial styloid centered over its distal articular surface. CT scanning may be necessary to establish the diagnosis if plain films are inconclusive. Immobilizing the wrist in supination reduces dorsal dislocations, whereas volar dislocations are placed in pronation. Patients with acute distal radioulnar joint disruption are referred acutely for orthopedic follow-up. These injuries have a high recurrence rate and may require reconstructive surgery, particularly if there is a delay in diagnosis. Acknowledgments: The authors wish to acknowledge the contribu tions of Robert Escarza; Maurice F . Loeffel, III; Dennis T. Uehara; Dean Wolanyk, MD; and Harold Chin, MD, for their work on previous edi tions of this chapter. REFERENCES The complete reference list is available online at www.TintinalliEM.com. Elbow and Forearm Injuries Yvonne C. Chow Stewart W. Lee ANATOMY Articulations of the distal humerus and proximal ulna and radius form the elbow joint (Figure 270-1). The distal humerus is comprised of the medial and lateral con dyles. The articulating surfaces of the medial and lateral condyles are the trochlea and the capitellum, respectively. Medially, the trochlea articulates with the olecranon of the ulna to form a uniaxial hinge joint. CHAPTER Tintinalli_Sec22_p1767-1880.indd 1809 8/2/19 6:15 PM

is comprised of the medial and lateral con dyles. The articulating surfaces of the medial and lateral condyles are the trochlea and the capitellum, respectively. Medially, the trochlea articulates with the olecranon of the ulna to form a uniaxial hinge joint. CHAPTER Tintinalli_Sec22_p1767-1880.indd 1809 8/2/19 6:15 PM 1810 SECTION 22: Orthopedics Laterally, the capitellum abuts the radial head to form a pivot joint. The medial and lateral epicondyles are nonarticulating surfaces where the forearm, wrist, and digit flexors and pronators (medial), and extensor and supinator (lateral) muscles originate. The radius and ulna articulate at their ends to form the proximal and distal radioulnar joints and are joined along their entire length by a fibrous interosseous membrane. The ulna is a fairly straight bone, whereas the radius has an important outward bowing. During supination and pronation, the radius rotates around the relatively fixed ulna. Because these bones have such a close relationship, injury to one will frequently impact the other. Several neurovascular structures lie in proximity to the distal humerus, and evaluation of their function is essential. These include the brachial artery and the radial, median, and ulnar nerves ( Table 270-1). The neuroanatomy is best understood by appreciating the neural control of wrist and finger movements (Figure 270-2). The radial nerve travels over the lateral epicondyle into the forearm before splitting into a deep branch that pierces through the supinator muscle and a superficial branch that lies adjacent to the radial artery. The proximal portion of Median nerve Humerus Humerus Radial nerve Ulnar nerve Medial (ulnar) collateral ligament Lateral (radial) collateral ligament Annular ligament Annular ligament Lateral epicondyle Brachial artery Median nerve Radius Ulna Radius Ulna FIGURE 270-1. Elbow anatomy. A. Anterior view. B. Lateral view. C. Medial view. TABLE 270-1 Sensory and Motor Function Testing of the Radial, Median, and Ulnar Nerves Radial Median Ulnar Sensory function (test with 2-point discrimination) Dorsum of the thumb and index web space Tip of the index finger Tip of the little finger Motor function (test against resistance) Extend wrist and fingers (“Rock” and “Paper” motions) “OK” sign with thumb and index finger; abduct thumb (“thumbs up” motion) Abduct index finger (“Scissors” motion) the radial nerve controls the more proximal function of wrist extension, the deep branch (posterior interosseous nerve) controls the more distal function of finger and thumb extension, and the superficial branch is purely sensory, providing sensation over the dorsal aspect of the hand from the thumb to the radial half of the ring finger. Thus, an isolated Tintinalli_Sec22_p1767-1880.indd 1810 8/2/19 6:15 PM

posterior interosseous nerve) controls the more distal function of finger and thumb extension, and the superficial branch is purely sensory, providing sensation over the dorsal aspect of the hand from the thumb to the radial half of the ring finger. Thus, an isolated Tintinalli_Sec22_p1767-1880.indd 1810 8/2/19 6:15 PM CHAPTER 270: Elbow and Forearm Injuries 1811 injury to the posterior interosseous branch affects finger extension but spares wrist extension and sensation to the dorsum of the hand. This can be seen in a compression neuropathy to the posterior interosseous nerve at the level of the supinator muscle. The proximal portion of the median nerve controls the muscles of wrist flexion and the superficial finger flexors before it gives off the anterior interosseous nerve, which controls the radial half of the deep finger flexors and thumb flexion at the interphalangeal joint. The remaining portion of the median nerve provides sensation to the volar surface of the hand from the thumb to the radial half of the ring finger, including the dorsal tips of the thumb, index, and middle fingers. A separate motor branch (recurrent branch of the median nerve) controls the thenar muscles for thumb opposition and abduction. The ulnar nerve innervates the forearm muscles and the intrinsic muscles of the hand while providing sensation to the little finger and the ulnar half of the ring finger. Proximal to the elbow, the ulnar nerve courses under a ligamentous band called the arcade of Struthers before entering the cubital tunnel posterior to the medial epicondyle. These are two sites where the nerve can become entrapped, leading to ulnar neu ropathy syndromes. The ulnar nerve is palpable as a cord in the cubital tunnel and is vulnerable to injury with trauma over this area. The biceps brachii muscle has two proximal heads and two distal attachments (Figure 270-3). The proximal long head originates proxi mal to the shoulder capsule, and the proximal short head originates at the coracoid process. The distal attachments are to the radial tuberosity by the distal biceps tendon and the forearm by the bicipital aponeurosis. The biceps muscle is innervated by the musculocutaneous nerve (C5 and C6) and functions primarily to supinate and assist in flexion of the forearm. The brachialis muscle lies deep to the biceps muscle. It is innervated by both the musculocutaneous and radial nerves (C5, C6, C7, and C8) and is the primary flexor of the forearm. The triceps muscle has three proximal heads ( Figure 270-4): a long head originating from the scapula, a lateral head, and a medial head. The triceps inserts at the olecranon via the triceps tendon. The triceps muscle is innervated by the radial nerve (C6, C7, and C8) and is the sole extensor of the forearm. The intrinsic forearm muscles include the brachioradialis, pronator teres, pronator quadratus, anconeus, and supinator (Figure 270-5). The motor functions of these muscles are summarized in Table 270-2. Motor intrinsics and sensory Finger flexors (Anterior interosseous nerve) Wrist flexors and flexor superficialis Sensory Sensory and thenar muscles Sensory AB C Finger extensors (Posterior interosseous nerve) Wrist extensors Few flexors FIGURE 270-2. Neural innervation of the forearm, wrist, hand, and digits. A. Radial nerve innervation. B. Median nerve innervation. C. Ulnar nerve innervation. Radial tuberosity Biceps aponeurosis Biceps brachii Tendon of short head Tendon of long head FIGURE 270-3. Biceps muscle anatomy. Tintinalli_Sec22_p1767-1880.indd 1811 8/2/19 6:15 PM

nnervation of the forearm, wrist, hand, and digits. A. Radial nerve innervation. B. Median nerve innervation. C. Ulnar nerve innervation. Radial tuberosity Biceps aponeurosis Biceps brachii Tendon of short head Tendon of long head FIGURE 270-3. Biceps muscle anatomy. Tintinalli_Sec22_p1767-1880.indd 1811 8/2/19 6:15 PM 1812 SECTION 22: Orthopedics Lateral head Long head Medial head Olecranon of ulna Triceps tendon Triceps brachiiTriceps brachii FIGURE 270-4. Triceps muscle anatomy. CLINICAL FEATURES  HISTORY A thorough history is essential for determining the correct diagnosis in a patient with elbow or forearm pain. Onset of symptoms, mecha nism of injury, exact location of pain, and associated symptoms such as Biceps brachii Long head Short head Brachialis Brachioradialis Pronator teres Pronator quadratus Biceps aponeurosis Palmaris longus Flexor carpi ulnaris Flexor retinaculum AnteriorAB Posterior Flexor carpi radialis Triceps brachii Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Anconeus Flexor carpi ulnaris Extensor carpi ulnaris Extensor digiti minimi Extensor digitorum Extensor retinaculum FIGURE 270-5. Intrinsic forearm muscles. A. Anterior forearm. B. Posterior forearm. numbness, weakness, or distal wrist and hand complaints are important elements to obtain. Most acute traumatic injuries to the elbow and forearm occur due to either a fall onto an outstretched hand or a direct blow. Chronic overuse injuries should correlate with preceding activity involving a repetitive motion. A history of arthritides may point to a systemic disorder such as lupus, rheumatoid arthritis, or gout.  PHYSICAL EXAMINATION Inspect the elbow and forearm for gross deformity, soft tissue swelling such as bursitis, or open wounds. Assess range of motion of the elbow in flexion, extension, pronation, and supination. Inability to fully extend the elbow is correlated with the presence of a fracture. 1 Conversely, full range of motion in all four planes has high negative predictive value for fracture. Radial, median, and ulnar nerve function can be conducted by isolated nerve testing. Test motor function against resistance. Assess sensory function using two-point discrimination. Test radial nerve motor function by having the patient extend both the wrist and fingers against resistance (Table 270-1). Assess sensation over the dorsum of the thumb index web space. Evaluate the median nerve through its distal branches— the anterior interosseous nerve and the recurrent branch of the median nerve. Assess anterior interosseous nerve function by having the TABLE 270-2 Motor Functions of the Intrinsic Forearm Muscles Muscle Function Brachioradialis Assists with forearm flexion Pronator teres Assists with forearm pronation and flexion Pronator quadratus Primary forearm pronation Anconeus Trivial forearm extension Supinator Primary forearm supination Tintinalli_Sec22_p1767-1880.indd 1812 8/2/19 6:15 PM

f the Intrinsic Forearm Muscles Muscle Function Brachioradialis Assists with forearm flexion Pronator teres Assists with forearm pronation and flexion Pronator quadratus Primary forearm pronation Anconeus Trivial forearm extension Supinator Primary forearm supination Tintinalli_Sec22_p1767-1880.indd 1812 8/2/19 6:15 PM CHAPTER 270: Elbow and Forearm Injuries 1813 Radial head Radial shaft Distal humerus Capitellum Capitellum Distal humerus FIGURE 270-6. A. Radiocapitellar line. B. Anterior humeral line. FIGURE 270-7. Anterior and posterior fat pad signs. patient make a circle, or “OK” sign, with the thumb and index finger. Abduction of the thumb through a “thumbs up” sign against resistance (recurrent branch of the median nerve) and sensory testing over the tip of the index finger complete the evaluation of the median nerve. Test ulnar nerve function by having the patient spread the fingers apart against resistance; sensation is tested over the tip of the fifth digit. A simple and thorough way to assess radial, median, and ulnar nerve motor function, particularly in children, is to have the patient perform the motions of the game Rock, Paper, Scissors, followed by the OK sign. 3 This routine includes the movements of wrist extension (proximal radial nerve), finger extension (posterior interosseous nerve branch of radial nerve), finger abduction (ulnar nerve), and thumb and finger flexion (anterior interosseous nerve branch of the median nerve) described above. DIAGNOSIS  IMAGING Initial imaging studies should include anteroposterior and lateral views of the elbow, and anteroposterior, lateral, and oblique views of the humerus and forearm. If a distal forearm injury is present, obtain anteroposterior, lateral, and oblique views of the wrist instead of the humerus. Clinical decision rules to guide imaging decisions for the elbow, similar to published ankle and knee imaging rules, have to date produced conflicting data and are not helpful. 1,4,5 On lateral films of the elbow, a line drawn straight through the center of the radial shaft (radiocapitellar line) should bisect the radial head and capitellum ( Figure 270-6A). Loss of this relationship should raise suspicion for an occult radius fracture or dislocation. A line drawn straight along the anterior border of the humerus (anterior humeral line) should transect the posterior two thirds of the capitellum (Figure 270-6B). Abnormal extension of the line through the anterior one third of the capitellum suggests a distal humerus (in adults) or supracondylar fracture (in children). A small anterior fat pad may be a normal finding. Large anterior and any posterior fat pads are always abnormal and indicate the presence of a joint effusion (Figure 270-7). Obtain CT imaging to evaluate for fracture when plain radiographs are normal in the setting of concerning physical exam findings. 6 CT also assists in characterizing certain elbow fractures, particularly coronoid and comminuted intra-articular fractures. MRI is useful in the evalua tion of soft tissue injuries but has a limited role in the acute setting. US can demonstrate effusions, fractures, postreduction fracture alignment, and tendon injury. 7-10 Several studies have demonstrated sensitivities and specificities of over 90% for the diagnosis of forearm and elbow fractures using point-of-care US. 11,12 While it cannot completely replace plain radiography due to variations in operator skill, point-of-care US can be a powerful diagnostic adjunct in the evaluation of elbow and forearm injuries. TREATMENT Consult an orthopedic surgeon immediately for open fractures, irreducible dislocations, injuries resulting in a grossly unstable elbow joint, nerve injury, or vascular injury with signs of ischemia or uncontrolled hemorrhage.

an be a powerful diagnostic adjunct in the evaluation of elbow and forearm injuries. TREATMENT Consult an orthopedic surgeon immediately for open fractures, irreducible dislocations, injuries resulting in a grossly unstable elbow joint, nerve injury, or vascular injury with signs of ischemia or uncontrolled hemorrhage. All other injuries may be referred for follow-up within 1 to 2 days for operative planning or up to a week for nonoperative treatment. Table 270-3 outlines guidelines for ED immobilization and appropriate orthopedic consult time frames for the conditions discussed in this chapter.  SOFT TISSUE INJURIES BICEPS TENDON RUPTURE Most biceps injuries are proximal, and nearly all of these involve the proximal long head. Injuries usually manifest as tendinopathies from repetitive microtrauma and overuse. The classic mechanism leading to tendon rupture is a sudden or prolonged contraction against resistance in middle-aged and older individuals with a history of chronic biceps tendinopathy. A snap or pop is usually described, and pain is present in the anterior shoulder. Examination of the anterior shoulder will reveal swelling, tenderness, and often crepitus over the bicipital groove. Ecchymosis may extend the entire length of the biceps. Flexion of the elbow will elicit pain and may produce a midarm “ball, ” which represents the distally retracted biceps muscle. Comparing arms for symmetry Tintinalli_Sec22_p1767-1880.indd 1813 8/2/19 6:16 PM

tenderness, and often crepitus over the bicipital groove. Ecchymosis may extend the entire length of the biceps. Flexion of the elbow will elicit pain and may produce a midarm “ball, ” which represents the distally retracted biceps muscle. Comparing arms for symmetry Tintinalli_Sec22_p1767-1880.indd 1813 8/2/19 6:16 PM 1814 SECTION 22: Orthopedics helps. Loss of flexion strength is minimal, due to the preserved functions of the brachialis and supinator. Avulsion fractures occasionally occur, so radiographs of the shoulder should be obtained. ED treatment includes sling, ice, analgesics, and referral to an orthopedic surgeon for definitive care. Distal biceps injuries are less common than proximal injuries. 13 Complete distal tendon ruptures are most common in middle-aged men and usually involve the dominant extremity. Partial tears are seen in men and women. Mechanism of injury is typically a sudden eccentric (extension) load applied to a flexed elbow. Pain is felt in the antecubital fossa, with swelling, ecchymosis, and tenderness to palpation noted on examina tion. A palpable defect in the antecubital fossa and a midarm “ball” may be present. Strength loss, especially supination, is more notable than with proximal ruptures. The biceps squeeze test , similar to the Thompson test for assessing Achilles tendon rupture, can detect biceps rupture. 14 With the patient seated and the forearm at 60 to 80 degrees of flexion, place one hand on the muscle belly of the biceps and the other hand on the myotendinous junction, and squeeze with both hands. The squeeze should result in forearm supination. Lack of supination is con sidered a positive test, indicating rupture of the distal biceps tendon. To perform the hook test, 15 flex the patient’s elbow to 90 degrees. During active supination, if the biceps tendon is intact, the examiner can “hook” the index finger under a cord-like structure in the antecubital fossa. Obtain elbow radiographs to search for an associated avulsion fracture. Although most complete distal ruptures are diagnosed clinically, US can aid in confirming the diagnosis of partial tears. 16,17 ED treatment includes sling, ice, analgesics, and referral to an orthopedic surgeon for definitive care. Although distal biceps ruptures were historically treated with surgery, management can be either surgical or conservative, depending on the patient.

ly, US can aid in confirming the diagnosis of partial tears. 16,17 ED treatment includes sling, ice, analgesics, and referral to an orthopedic surgeon for definitive care. Although distal biceps ruptures were historically treated with surgery, management can be either surgical or conservative, depending on the patient. TABLE 270-3 Immobilization and Follow-Up Guidelines Injury Splint Referral Soft tissue injuries Biceps tendon rupture Triceps tendon rupture Lateral/medial epicondylitis Sling immobilization Sling immobilization Rigid wrist brace, forearm counterforce brace 1 wk 1 wk 2–4 wk PRN Elbow dislocation Stable/postreduction Unstable/postreduction Irreducible Long arm posterior splint, elbow slightly less than 90 degrees, forearm neutral Long arm posterior splint (presurgical stabilization) Long arm posterior splint (presurgical stabilization) 1–2 d Immediate Immediate Elbow fractures Distal humerus nondisplaced Supracondylar Intercondylar Lateral condyle/epicondyle Nondisplaced Displaced Medial condyle/epicondyle Nondisplaced Displaced Articular surface Coronoid Nondisplaced or minimally displaced Markedly displaced or unstable Olecranon Radial head Nondisplaced Displaced or range of motion block Long arm posterior splint, forearm neutral Long arm posterior splint (presurgical stabilization) Long arm posterior splint, forearm neutral Long arm posterior splint, forearm in supination Long arm posterior splint (presurgical stabilization) Long arm posterior splint, forearm in pronation Long arm posterior splint (presurgical stabilization) Long arm posterior splint, forearm neutral Long arm posterior splint, elbow past 90 degrees, forearm in supination Long arm posterior splint (presurgical stabilization) Long arm posterior splint, forearm neutral Sling immobilization with early range of motion Long arm posterior splint, forearm neutral 1 wk <24 h 1–2 d 1–2 d Immediate 1–2 d Immediate 1–2 d 1–2 d Immediate <24 h 1 wk <24 h Forearm fractures Both bones Pediatric Greenstick Displaced Adult Nondisplaced Displaced Isolated ulna shaft Proximal two thirds of radius Nondisplaced Displaced Monteggia’s Galeazzi’s Long arm posterior splint Long arm posterior splint Sugar-tong splint Long arm posterior splint (presurgical stabilization) Long arm posterior splint, forearm neutral or sugar-tong splint if stable and nondisplaced Long arm posterior splint, forearm neutral Long arm posterior splint, forearm neutral Long arm posterior splint (presurgical stabilization) Long arm posterior splint (presurgical stabilization) 1 wk Immediate 1 wk <24 h 1 wk 1 wk 1–2 d Immediate Immediate Tintinalli_Sec22_p1767-1880.indd 1814 8/2/19 6:16 PM

ondisplaced Long arm posterior splint, forearm neutral Long arm posterior splint, forearm neutral Long arm posterior splint (presurgical stabilization) Long arm posterior splint (presurgical stabilization) 1 wk Immediate 1 wk <24 h 1 wk 1 wk 1–2 d Immediate Immediate Tintinalli_Sec22_p1767-1880.indd 1814 8/2/19 6:16 PM CHAPTER 270: Elbow and Forearm Injuries 1815 TRICEPS TENDON RUPTURE Injury to the triceps is rare and almost always occurs distally.19 Ruptures result from either a fall on an outstretched hand causing a forceful flexion of an extended elbow or a direct blow to the olecranon. Pain is felt in the posterior elbow. Examination of the elbow reveals posterior swelling and tenderness, just proximal to the olecranon. A sulcus with a more proximal mass, representing the retracted triceps muscle, may be palpable. With partial tears, some degree of function remains; however, with complete ruptures, the ability to extend the elbow is lost. A modified Thompson test can be used to evaluate triceps function. The upper extremity is positioned such that the arm is supported and the forearm is hanging in a relaxed position with 90 degrees of flexion. Squeezing the triceps muscle should produce extension of the forearm, unless a com plete rupture is present. Radiographs of the elbow are needed because avulsion fractures of the olecranon are common. Point-of-care US can aid in diagnosis, especially of partial tears. 20,21 ED treatment includes sling, ice, analgesics, and referral to an orthopedic surgeon for definitive care. Complete ruptures require surgical repair, whereas most partial tears can be treated conservatively with immobilization. LATERAL EPICONDYLITIS Lateral epicondylitis, or “tennis elbow, ” is an overuse syndrome affecting the wrist and digit extensors and the forearm supinators. The diagnosis is made clinically by tenderness over the lateral epicondyle and pain with resisted wrist extension, digit extension, and forearm supination. Treatment is usually conservative, with rest, friction massage, anti-inflammatory medications, immobilization with a rigid wrist brace to limit wrist extension or a counterforce forearm brace, and physical therapy. Refer to an orthopedic surgeon or sports medicine specialist for follow-up care. 22-24 MEDIAL EPICONDYLITIS The less common counterpart to lateral epicondylitis is medial epicon dylitis (“golfer’s elbow”). As with lateral epicondylitis, the diagnosis is made clinically. Tenderness over the medial epicondyle and pain with resisted wrist flexion and forearm pronation are expected, as these are the muscle groups affected. In addition, patients may develop an ulnar neuropathy, given the proximity of the ulnar nerve to the medial epi condyle. Ulnar neuropathy requires orthopedic follow-up. Treatment is similar to that of lateral epicondylitis, with rest, anti-inflammatory medications, bracing, and physical therapy.  ELBOW DISLOCATION The elbow is one of the more stable joints. The muscular attachments, lateral collateral ligament, and medial ulnar collateral ligament augment its inherent stability in the flexion-extension plane. Dislocations of the elbow rank third in large-joint dislocations, after glenohumeral and patellofemoral dislocations. The mechanism of injury is usually a fall on an outstretched hand. Approximately 90% of all elbow dislocations are posterolateral. 25 Fractures of the coronoid process, radial head, medial epicondyle, and olecranon can complicate the treatment of elbow dislocations. The “terrible triad” injury consists of an elbow dislocation coupled with fractures of the radial head and coronoid. This injury cre ates an unstable joint and requires emergent orthopedic consultation. Clinically, the patient presents with the elbow in 45 degrees of flexion.

licate the treatment of elbow dislocations. The “terrible triad” injury consists of an elbow dislocation coupled with fractures of the radial head and coronoid. This injury cre ates an unstable joint and requires emergent orthopedic consultation. Clinically, the patient presents with the elbow in 45 degrees of flexion. The olecranon is prominent posteriorly, and the deformity resembles a displaced supracondylar fracture. If the patient is seen immediately after the injury, the bony landmarks can be identified. Later, however, the swelling may be quite severe, with no possibility of evaluating the injury topographically. The priority is to assess the neurovascular status of the brachial artery, ulnar nerve, and median nerve, as these structures may become entrapped. Perform neurovascular examina tion before and after manipulation. Neurologic complications most frequently involve the ulnar nerve and occur in up to 20% of elbow dislocations. Brachial artery injuries are estimated to occur in 5% to 13% of elbow dislocations. 26 Absence of a radial pulse before reduction, an open dislocation, and systemic injuries (such as those of the head, chest, and abdomen) are findings associated with arterial injury. 27,28 If vascular injury is suspected, then angiography may be required to assess the extent of injury and need for repair. On the lateral radiograph, both the ulna and radius are displaced posteriorly (Figure 270-8). In the anteroposterior view, there may be lateral or medial displacement, with the ulna and radius in their normal relationship to each other. Assess for associated fractures, particularly of the coronoid process and radial head. Due to the amount of force that is necessary to reduce a dislocated elbow, success often depends on IV analgesia or procedural sedation. Intra-articular lidocaine is also helpful for closed reduction of dislocated elbows. Regardless of the type of analgesia used, ensure appropriate patient comfort prior to attempting closed reduction. Closed reduction can be accomplished by several methods. In the first two-person reduction technique, position the forearm supine. While an assistant applies a stabilizing countertraction force on the upper arm, use one hand to apply a longitudinal traction on the wrist and forearm (Figure 270-9). With the other hand, manipulate the elbow to correct any medial or lateral displacement. Then apply slow and steady downward pressure to the proximal forearm with the other hand to help disengage the coronoid process from the olecranon fossa. Continue distal traction and flex the elbow. In the second two-person technique, the patient is prone with the arm abducted and the elbow slightly flexed. The patient may also be supine with the arm adducted across the torso and the elbow slightly flexed ( Figure 270-10). Have an assistant apply longitudinal traction on the wrist and forearm. Then, grasp the elbow, positioning both thumbs on the olecranon, and apply firm pressure against the olecranon to push it up and over the trochlea and back into anatomic position. Apply countertraction with the fingers against the distal humerus. A preliminary report described a single-person reduc tion technique with the patient in a seated position ( Figure 270-11). Place an elbow in the patient’s antecubital fossa, then grasp the patient’s hand or wrist. Flex the patient’s forearm while leveraging a force into the antecubital fossa to bring the olecranon back into anatomic position. As this is a preliminary report of the technique, success and complication rates are not known with certainty. The last technique is a modifica tion of the Stimson hanging technique used in shoulder reductions (Figure 270-12). Place the patient prone with the elbow flexed over the edge of the stretcher.

tomic position. As this is a preliminary report of the technique, success and complication rates are not known with certainty. The last technique is a modifica tion of the Stimson hanging technique used in shoulder reductions (Figure 270-12). Place the patient prone with the elbow flexed over the edge of the stretcher. Support the humerus proximal to the elbow with a folded blanket or pillow. Suspend 5-lb weights from the wrist. The patient’s elbow should reduce over a period of several minutes. Gentle manipulation may be applied to the olecranon to aid reduction. With reduction, a palpable “clunk” is felt as the olecranon is seated back in the trochlea. Move the elbow through its full range of motion to assess stability. Obtain postreduction films to determine reduction and identify fractures not previously identified. Inability to maintain FIGURE 270-8. Posterior elbow dislocation. Tintinalli_Sec22_p1767-1880.indd 1815 8/2/19 6:16 PM

n is seated back in the trochlea. Move the elbow through its full range of motion to assess stability. Obtain postreduction films to determine reduction and identify fractures not previously identified. Inability to maintain FIGURE 270-8. Posterior elbow dislocation. Tintinalli_Sec22_p1767-1880.indd 1815 8/2/19 6:16 PM 1816 SECTION 22: Orthopedics reduction necessitates emergency orthopedic consultation. If the joint is stable and good neurovascular status has been confirmed, splint with a long arm posterior splint with the forearm and wrist both in neutral position and the elbow at slightly less than 90 degrees of flexion. Arrange orthopedic follow-up in 1 to 2 days. 29,30 Obtain emergency orthopedic consultation for irreducible disloca tions, neurovascular compromise, postreduction instability, associated fractures, and open dislocations.  FRACTURES ABOUT THE ELBOW Elbow fractures can be divided into those of the distal humerus, proxi mal ulna, and proximal radius. The distal humerus includes the condy lar structures and the articular surface (trochlea and capitellum). The proximal ulna includes the coronoid process and olecranon, and the proximal radius is essentially the radial head. Radiographs of fractures about the elbow may reveal abnormal fat pads (Figure 270-7). A traumatic hemarthrosis displaces fat from the olecranon fossa posteriorly (posterior fat pad), and the anterior fat pad may become prominent (“sail sign”). However, abnormal fat pads may also be seen with nontraumatic joint effusions. Furthermore, they may be absent in severe trauma that disrupts the joint capsule and allows intra-articular fluid extravasation. In some nondisplaced fractures, the fracture line may not be seen, with the fat pad sign being the only evi dence of injury. Treatment is initiated as though a fracture were identi fied, with splint immobilization and orthopedic consultation. DISTAL HUMERUS FRACTURES Routine ED care of nondisplaced distal humerus fractures with nor mal neurovascular function includes immobilization, ice, elevation, analgesics, and orthopedic referral. Displaced fractures or those with neurovascular compromise require immediate orthopedic consultation. See Chapter 271, “Shoulder and Humerus Injuries, ” for a detailed discussion of shoulder and humerus injuries. SUPRACONDYLAR FRACTURES Supracondylar fractures are the most common fracture about the elbow in children between 5 and 10 years of age, but can occur in adults, especially from high-velocity injuries. Fractures can be either extension type (>95%), which are displaced posteriorly, or flexion type (<5%), which are displaced anteriorly. Treatment varies widely between nonoperative management to emergent surgical management. In 2014, the American Academy of Orthopedic Surgeons developed recommendations on the management of supracondylar fractures based on various clinical scenarios called the Appropriate Use Criteria for the Management of Pediatric Supracondylar Humerus Fractures. 31 Due to the complexity of these guidelines, the authors recommend emergency orthopedics consultation. However, a more conservative approach with urgent, rather than emergent, fixation has become more common. Treatment largely depends on the degree of displacement of the distal fragment and any concurrent neurovascular or soft tissue injury.  EXTENSION-TYPE SUPRACONDYLAR FRACTURES Injuries most often occur with a fall on an outstretched hand with the elbow in full extension. Examination reveals significant edema and tenderness at the elbow, a prominent olecranon, and a depression proximal to the elbow. The appearance may be easily mistaken for a posterior elbow dislocation.

PRACONDYLAR FRACTURES Injuries most often occur with a fall on an outstretched hand with the elbow in full extension. Examination reveals significant edema and tenderness at the elbow, a prominent olecranon, and a depression proximal to the elbow. The appearance may be easily mistaken for a posterior elbow dislocation. Nondisplaced fractures may be subtle and diagnosed only by the presence of a posterior fat pad, anterior “sail sign, ” or disruption to the normal path of the anterior humeral line. Initially treat with FIGURE 270-9. Traction and flexion reduction method. A. Side-to-side manipulation is used to correct medial or lateral displacement. B. The elbow is then flexed while maintaining longitudinal traction. Tintinalli_Sec22_p1767-1880.indd 1816 8/2/19 6:16 PM

he normal path of the anterior humeral line. Initially treat with FIGURE 270-9. Traction and flexion reduction method. A. Side-to-side manipulation is used to correct medial or lateral displacement. B. The elbow is then flexed while maintaining longitudinal traction. Tintinalli_Sec22_p1767-1880.indd 1816 8/2/19 6:16 PM CHAPTER 270: Elbow and Forearm Injuries 1817 immobilization using a long arm posterior splint, keeping the elbow at 90 degrees of flexion and the forearm in neutral rotation, followed by outpatient referral for casting. The presence of >20 degrees of angulation necessitates orthopedic consultation for reduction under anesthesia and possible pin fixation. 32 In displaced fractures, the distal fragment will be displaced proximally and posteriorly. More severely displaced fractures may show medial or lateral displacement or rotation along the axis of the humerus ( Figure 270-13). Displaced fractures must be reduced and require orthopedic consultation. Historically, these fractures were treated with immediate reduction and pinning. However, there is now a trend toward delayed reduction and fixation up to 24 hours after injury without evidence of complication, thus lessening the need for emergent orthopedic intervention. 31,33-36 Indications for emergent consultation are vascular insufficiency or decreased perfusion, nerve injury, open fracture, or an irreducible fracture. Admit patients with displaced frac tures or significant soft tissue swelling for observation of neurovascular function.  FLEXION-TYPE SUPRACONDYLAR FRACTURES Flexion-type fractures are rare. The mechanism of injury is a direct anterior force against a flexed elbow, resulting in anterior displacement of the distal fragment. Because the mechanism is direct force, these fractures are often open. Management of flexion-type fractures is identical to that for extension-type fractures, with the same criteria for determining emergent versus urgent orthopedic consult. Flexion-type injuries are more likely to require open reduction and pinning, particularly if an associated ulnar nerve injury is present.  COMPLICATIONS OF SUPRACONDYLAR FRACTURES There are numerous potential complications of supracondylar frac tures (Table 270-4). Neurologic complications—resulting from trac tion, direct trauma, or nerve ischemia—have an incidence of 10% to 20%. 38 Ulnar nerve injuries are uncommon, with the highest incidence reported iatrogenically from pin placement. Posteromedial displace ment may involve the radial nerve, and posterolateral displacement can affect the median nerve. There is a high incidence of anterior interos seous nerve injuries with supracondylar fractures . The mechanism of injury is usually traction or contusion. Complete transection is rare, and entrapment within the fracture occurs only occasionally. Because there is no sensory component to the anterior interosseous nerve, the injury can only be identified through motor testing by making the “OK” sign. Always suspect acute neurovascular injuries in patients with supracondylar fractures. Absence of a radial pulse is an indicator of brachial artery injury, even if the hand appears warm, pink, and well perfused. Injury can be due to a partial or complete transection, an intimal tear and thrombosis, or entrapment within the fracture fragment of the brachial artery. Suspected or actual neurovascular injury requires emergency orthopedic consultation. 41,42 The most serious complication is a compartment syndrome of the forearm, also known as Volkmann’s ischemic contracture. This classically occurs following a displaced supracondylar fracture. Postischemic swelling increases pressure within the enclosed osteofascial forearm compartment and reduces capillary blood perfusion below the level necessary for tissue viability.

yndrome of the forearm, also known as Volkmann’s ischemic contracture. This classically occurs following a displaced supracondylar fracture. Postischemic swelling increases pressure within the enclosed osteofascial forearm compartment and reduces capillary blood perfusion below the level necessary for tissue viability. If unrelieved, the result is muscle and nerve necrosis and eventual replacement by fibrotic tissue, producing a contracture. Refusal to open the hand, pain with passive extension of the fingers, and forearm pain out of proportion to exam findings are signs of impending Volkmann’s ischemia. Extremities with signs of ischemia require emergency orthopedic consultation. INTERCONDYLAR FRACTURES Intercondylar fractures, in which the condylar fragments are separated, are much more common in adults than in children. Assume any distal humerus fracture in an adult to be intercondylar rather than supracondylar. The mechanism of injury is a force directed against the posterior elbow. This drives the olecranon against the humeral articular surface, FIGURE 270-10. Olecranon manipulation reduction method with the patient posi tioned (A) prone or (B) supine. FIGURE 270-11. Single-person reduction method. Tintinalli_Sec22_p1767-1880.indd 1817 8/2/19 6:16 PM

a force directed against the posterior elbow. This drives the olecranon against the humeral articular surface, FIGURE 270-10. Olecranon manipulation reduction method with the patient posi tioned (A) prone or (B) supine. FIGURE 270-11. Single-person reduction method. Tintinalli_Sec22_p1767-1880.indd 1817 8/2/19 6:16 PM 1818 SECTION 22: Orthopedics separating the condyles and producing the fracture. Carefully search for a fracture line separating the condyles from each other and from the humerus. All intercondylar fractures involve the articular surface. CT imaging is useful for identifying comminuted fractures and for planning operative therapy for displaced fractures. Treatment is dependent on the amount of displacement of the fracture fragments. Nondisplaced intercondylar fractures are stable and can be treated initially with immobilization in a long arm posterior splint with the elbow flexed at 90 degrees and the forearm in neutral position. Obtain orthopedic consultation for treatment of displaced, rotated, or commi nuted fractures or severe edema. EPICONDYLE FRACTURES Lateral epicondyle fractures are uncommon, because the anatomic position of the condyle reduces its exposure to direct blows. When they do occur, lateral epicondyle fractures are usually avulsion fractures. These can be treated with immobilization in a long arm posterior splint, with the elbow flexed to 90 degrees and the forearm in supination, and orthopedic referral. Isolated medial epicondyle fractures are considered extra-articular injuries and usually occur in children and adolescents. Mechanisms include a posterior elbow dislocation, repeated valgus stress such as throwing a baseball (Little League elbow), or a direct blow. If there is an associated tear of the medial (ulnar) collateral ligament, the epicondyle itself may become entrapped in the joint space. Patients present with pain over the medial elbow that is exacerbated by supination of the forearm and flexion of the forearm, wrist, and digits. Edema and tenderness are noted in the same area. Carefully test neurovascular function. Obtain standard radiographs with special attention to any intra-articular fragment. Comparison views of the unaffected contralateral elbow may be helpful for diagnosis. Treat stable, nondisplaced or minimally displaced fractures from a low-energy mechanism nonoperatively, with early range of motion. ED treatment consists of long arm posterior splint immobilization, with the forearm in flexion and pronation, and orthopedic referral. High-energy injuries, open fractures, unstable joints, significant fragment displace ment, an intra-articular fragment, and ulnar neuropathy are indications for emergency orthopedic consultation. 44-46 Because surgical treatment should be determined on an individual basis, orthopedic consultation is recommended for all epicondyle fractures. CONDYLE FRACTURES Lateral condyle fractures occur in children and are more common than their medial counterpart. 47 They result from either a direct blow to the lateral elbow or from a fall on an outstretched hand. Patients complain of pain in the lateral elbow, and swelling is noted in the same area. FIGURE 270-13. Extension-type, displaced supracondylar fracture. TABLE 270-4 Complications of Supracondylar Fractures Early complications Neurologic Radial nerve injury Median nerve injury (anterior interosseous branch) Ulnar nerve injury (iatrogenic) Vascular Brachial artery injury Volkmann’s ischemic contracture (compartment syndrome of the forearm) Late complications Nonunion Malunion Myositis ossificans Loss of motion FIGURE 270-12. A. Hanging arm reduction method. B. Gentle manipulation can be applied to the olecranon if necessary. Tintinalli_Sec22_p1767-1880.indd 1818 8/2/19 6:16 PM

y injury Volkmann’s ischemic contracture (compartment syndrome of the forearm) Late complications Nonunion Malunion Myositis ossificans Loss of motion FIGURE 270-12. A. Hanging arm reduction method. B. Gentle manipulation can be applied to the olecranon if necessary. Tintinalli_Sec22_p1767-1880.indd 1818 8/2/19 6:16 PM CHAPTER 270: Elbow and Forearm Injuries 1819 Medial condyle fractures are uncommon and are mostly limited to children. Mechanism of injury is from either a fall on an outstretched hand or excessive valgus stress. Medial pain and swelling are the prominent findings. The injury is often confused with the more common medial epicondyle fracture for two reasons. First, the mechanism and examination findings are similar. Second, because the trochlea ossifica tion center does not appear until age 9 to 10 years old, it is often missed on radiographs. ED care of nondisplaced condyle fractures with normal neurovas cular function includes long arm posterior splint immobilization, ice, elevation, analgesics, and orthopedic referral. Follow-up imaging every 2 weeks is recommended due to the risk of late displacement, which is treated with surgical fixation. Displaced fractures or those with neuro vascular compromise require immediate orthopedic consultation.  ARTICULAR SURFACE FRACTURES TROCHLEA AND CAPITELLUM FRACTURES Isolated trochlea fractures are rare and are often associated with other elbow injuries, such as posterior elbow dislocations. Physical findings usually include swelling, tenderness, and limited movement of the elbow joint. Radiographic findings can be subtle, and CT or MRI may be required for diagnosis. Isolated capitellum fractures are also rare. They are usually associated with radial head fractures. Pain is present over the lateral elbow, and examination reveals lateral swelling, tenderness, and limitation of flexion and extension. If pain and tenderness are present medially, then suspect injury to the medial (ulnar) collateral ligament. Radiographic findings may be subtle and are best seen on a lateral view. The capitellum has no tendinous or ligamentous attachments, so many fractures are nondisplaced. A radial head–capitellum view can be helpful in addition to standard anteroposterior and lateral views. CT imaging is useful for diagnosis. ED treatment of articular surface fractures includes long arm poste rior splint immobilization and orthopedic consultation. Complications are common and include limited flexion and extension, elbow joint instability, avascular necrosis, nonunion, and arthritis.  PROXIMAL ULNA FRACTURES Nearly all proximal ulna fractures are considered intra-articular, except for proximal olecranon chip fractures. CORONOID FRACTURES Coronoid fractures are usually associated with posterior elbow disloca tions as the trochlea impacts the coronoid. Rarely, a coronoid fracture can occur as an isolated injury secondary to elbow hyperextension. There is pain, swelling, and tenderness over the antecubital fossa. Radiographic visualization is best with lateral and oblique films. CT is often needed to make the diagnosis. ED treatment should include long arm posterior splint immobiliza tion with the elbow in flexion and the forearm in supination, ice, elevation, analgesics, and referral to an orthopedic surgeon within 24 hours. Due to the critical role the coronoid plays in elbow stability, early orthopedic referral is indicated even for isolated, nondisplaced fractures. Displaced fractures or those with joint instability require open reduction and internal fixation and frequently have poor outcomes. OLECRANON FRACTURES Olecranon fractures represent up to 10% of upper extremity fractures. 50 The mechanism is usually direct trauma or by a fall with forced hyper extension of the elbow.

. Displaced fractures or those with joint instability require open reduction and internal fixation and frequently have poor outcomes. OLECRANON FRACTURES Olecranon fractures represent up to 10% of upper extremity fractures. 50 The mechanism is usually direct trauma or by a fall with forced hyper extension of the elbow. Associated injuries are common, including open fractures, dislocations, other fractures (especially of the radial head), and ulnar nerve injury. Pain is present over the posterior elbow, and examination reveals swelling, tenderness, and occasionally crepitus. Because the triceps muscle inserts at the olecranon, elbow extension can be compromised. It is important to test extension against resistance, as the patient may falsely appear to have intact extension function by using gravity to draw the forearm down. Ulnar nerve injury is common; therefore, a careful neurologic examination is required. Lateral radiographs offer the best view of the olecranon. In adolescents, the epiphysis ossifies by 11 years of age and fuses by 16 years of age, so comparison films and the appearance of an abnormal fat pad can aid in the diagnosis. ED treatment includes long arm posterior splint immobilization with the elbow in flexion and forearm neutral, ice, elevation, analgesics, and referral to an orthopedist within 24 hours. Stable, nondisplaced fractures with intact extensor function can be treated conservatively with immobiliza tion. Nonoperative treatment may also be considered for elderly patients who are poor candidates for surgery. All other olecranon fractures require surgical repair.  RADIAL HEAD FRACTURES Radial head fractures are the most common fractures of the elbow. They result from a fall on an outstretched hand, causing the radial head to drive into the capitellum. Associated injuries are common and may include capitellum, olecranon, and coronoid fractures, medial collateral ligament injury, medial epicondyle avulsion fracture, and elbow dislocation. A specific associated injury, the Essex-Lopresti lesion, occurs when there is disruption of the triangular fibrocartilage complex of the wrist and the interosseous membrane between the radius and ulna, causing dissociation of the distal radioulnar joint. This is analogous to a Maisonneuve injury in the lower extremity. Do not miss this injury. Failure to recognize this injury can result in proximal migration of the radius, so obtain emergency orthopedic consultation. Radial head fractures cause pain in the lateral elbow, especially with pronation and supination of the forearm. On examination, there may be swelling laterally and tenderness with palpation of the radial head. Pronating and supinating the forearm with the elbow flexed allows the examiner to palpate the radial head. On standard elbow radiographs, radial head fractures may be subtle ( Figure 270-14). Radiographic FIGURE 270-14. Subtle radial head fracture and anterior fat pad sign ( arrow). Tintinalli_Sec22_p1767-1880.indd 1819 8/2/19 6:16 PM

pinating the forearm with the elbow flexed allows the examiner to palpate the radial head. On standard elbow radiographs, radial head fractures may be subtle ( Figure 270-14). Radiographic FIGURE 270-14. Subtle radial head fracture and anterior fat pad sign ( arrow). Tintinalli_Sec22_p1767-1880.indd 1819 8/2/19 6:16 PM 1820 SECTION 22: Orthopedics clues include the presence of an abnormal fat pad or abnormal displacement of the radiocapitellar line away from the center of the capitellum (Figure 270-7). This is especially helpful in children whose epiphysis has not fused. Additional images, including obliques and a radial head– capitellum view, may be helpful. Nondisplaced fractures can be treated conservatively with immobili zation and early range of motion exercises to avoid the development of a stiff joint. ED treatment consists of sling immobilization, ice, elevation, analgesics, and referral to an orthopedic surgeon or sports medicine specialist within 1 week. Consider aspiration of the joint hematoma in the ED to improve pain and facilitate early mobilization. 52 For displaced fractures or those with restricted range of motion, surgical repair is generally indicated, and orthopedic referral should be made within 24 hours. Complications of radial head fracture include chronic pain and restricted range of motion at the elbow.  FOREARM FRACTURES In adults, solitary fractures of the forearm are uncommon due to the close relationship of the radius and ulna. The fibrous interconnection between the radius and ulna transmits force above and below the injury. As a result, fractures usually occur at two or more sites or involve liga mentous injury or joint dislocation. Because distant structures are commonly injured, examine joints above and below the involved bones both clinically and radiologically. Be suspicious for associated injuries if there is significant angulation of the fracture. FRACTURES OF BOTH RADIUS AND ULNA A large amount of force is necessary to fracture both the radius and the ulna. This occurs most often from vehicular trauma, falls from a height, or a direct blow. Force magnitude determines the injury type. Moder ate forces produce transverse or mildly oblique fractures. High-impact forces produce comminuted and segmental fractures (often displaced). Nondisplaced fractures of both bones are exceedingly rare, because the force necessary to produce the injury is also sufficient to displace the bones. Examination of the forearm reveals swelling, deformity, and tenderness. Carefully assess the neurovascular status. Nerve injuries can occur with severe open fractures, but are uncommon with closed injuries. Because of the excellent collateral circulation of the forearm, vascular compromise is generally not a major concern if either the radial or ulnar circulation is intact. The fractures are clearly visible on radiographs. Note the degree of angulation, displacement, and shortening. Changes in rotational align ment may be subtle. Assessing the orientation of bony prominences on the radius and ulna can help determine rotational alignment. On the anteroposterior view, the radial styloid and radial (bicipital) tuberosity normally point in opposite directions, whereas the ulnar styloid and coronoid process do so on the lateral view. A change in this arrangement suggests rotation malalignment. Because these bones are oblong rather than circular in their cross-sectional appearance, a sudden change in the bone’s width at the fracture site is another clue to a rotational deformity. Obtain radiographs of the wrist and elbow because of the likelihood of an associated dislocation or articular fracture. Treatment depends on the type of fracture.

rather than circular in their cross-sectional appearance, a sudden change in the bone’s width at the fracture site is another clue to a rotational deformity. Obtain radiographs of the wrist and elbow because of the likelihood of an associated dislocation or articular fracture. Treatment depends on the type of fracture. Torus or greenstick frac tures with minimal angulation in children can be treated with immobi lization in a long arm splint. Angulation >15 degrees warrants referral for closed reduction. In younger children, treat displaced fractures with closed reduction and cast immobilization due to the continued remodeling that occurs after fracture healing. Perform closed reduction urgently in the ED to ensure appropriate alignment. Traditionally, closed reduction is performed by an orthopedic consultant, but reductions performed by emergency physicians for nonoverlapping fractures have also been show shown to have good outcomes. 53 Surgical intervention is indicated if acceptable reduction cannot be achieved through closed reduction and casting. 54 Nondisplaced fractures in adults can be immo bilized with a long arm splint and referred for urgent follow-up. All other fractures in adults require orthopedic consultation, ideally within 24 to 48 hours. Complications include reduced ability to supinate and pronate, osteomyelitis, nonunion, malunion, neurovascular injury, and compartment syndrome. Recognizing the development of a compartment syndrome is particularly important to prevent Volkmann’s ischemic contrac tures of the forearm. Direct measurements of elevated compartment pressures confirm the diagnosis. Emergent orthopedic consultation for fasciotomy is required. ULNA FRACTURES  ISOLATED ULNA FRACTURE (NIGHTSTICK FRACTURE) Isolated fractures of the ulna most often result from a direct blow to the forearm. A fracture resulting from the natural response to raise the forearm in defense of a strike is referred to as a nightstick fracture. Nondisplaced fractures are immobilized in a sugar-tong splint and closely followed for subsequent displacement. Fractures with >50% displacement, with >10% angulation, or that involve the proximal third of the ulna are considered unstable. Obtain orthopedic consultation for unstable fractures. Assess for any concomitant radius fracture or dislocation.  MONTEGGIA’S FRACTURE-DISLOCATION Fracture of the proximal third of the ulna with a radial head disloca tion is referred to as Monteggia’s fracture-dislocation (Figure 270-15). The associated radial head dislocation may be easily missed. 56 Missing the radial head dislocation can lead to chronic pain, limited range of motion, and, possibly, radial head excision as treatment. Monteggia’s fracture-dislocations occur following a fall onto an outstretched hand or a direct blow. Clinically, there is considerable pain and swell ing at the elbow. The radial head may be palpable in an anterolateral or posterolateral location. The forearm may appear shortened and angulated. The ulnar fracture is clearly visible on radiographs and may overshadow the less obvious radial head dislocation. An abnormal FIGURE 270-15. Monteggia’s fracture-dislocation. The angulation of the comminuted fracture of the proximal ulna points in the direction of the radial head dislocation. Tintinalli_Sec22_p1767-1880.indd 1820 8/2/19 6:16 PM