Elbow fractures can be divided into those of the distal humerus, proximal ulna, and proximal radius. The distal humerus includes the condylar 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 270-9).28 Normally, a posterior fat pad is not visible, and an anterior fat pad may be visible as a thin lucent stripe. With injury, fat from the olecranon fossa is displaced posteriorly (posterior fat pad), and the anterior fat pad may become quite prominent ("sail sign") due to hemarthrosis. 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 evidence of injury. Treatment is initiated as though a fracture were identified, with splint immobilization and orthopedic consultation.
Routine ED care of nondisplaced distal humerus fractures with normal 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 are the most common fracture about the elbow in children between 5 and 10 years of age, but can occur in adults, especially as a result of high-velocity injuries. Fractures can be either extension type (>95%), which are displaced posteriorly, or flexion type (<5%), which are displaced anteriorly. Treatment largely depends on the degree of displacement of the distal fragment.
EXTENSION-TYPE SUPRACONDYLAR FRACTURES
Injuries most often occur with a fall on an outstretched hand with the elbow in full extension. The patient will have 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 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.29 In displaced fractures, the anteroposterior radiograph usually reveals a transverse fracture line. More severely displaced fractures may show medial or lateral displacement or rotation along the axis of the humerus (Figure 270-15). The lateral radiograph will reveal the fracture line extending obliquely from posterior proximal to anterior distal. The distal fragment will be displaced proximally and posteriorly. Displaced fractures must be reduced and require orthopedic consultation. Indications for open reduction are vascular insufficiency with a probable entrapped brachial artery in the fracture site or an irreducible fracture. Admit patients with displaced fractures or significant soft tissue swelling for observation of neurovascular function.
Extension-type, displaced supracondylar fracture.
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. Radiographs reveal an oblique fracture from anterior proximal to posterior distal. The distal fragment is anterior to the humerus. Displaced fractures must be reduced and require immediate orthopedic consultation. Indications for open reduction are vascular insufficiency with a probable entrapped brachial artery in the fracture site or an irreducible fracture. Admit patients with displaced fractures or significant soft tissue swelling for observation of neurovascular function.
COMPLICATIONS OF SUPRACONDYLAR FRACTURES
There are numerous potential complications of supracondylar fractures (Table 270-3). Neurologic complications—resulting from traction, direct trauma, or nerve ischemia—have an incidence of 7%. Posteromedial displacement may involve the radial nerve, and posterolateral displacement usually affects the median nerve. Ulnar nerve injuries are uncommon, with the highest incidence reported from pin placement. However, a high incidence has been noted of anterior interosseous nerve injuries with supracondylar fractures. This nerve arises from the median nerve. 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, identification of the injury can be made only by motor testing, which consists of flexion at the index finger distal interphalangeal and thumb interphalangeal joints (making the "OK" sign). Patients usually regain full flexion and strength after 4 to 17 weeks.30
TABLE 270-3Complications of Supracondylar Fractures ||Download (.pdf) TABLE 270-3 Complications of Supracondylar Fractures
|Early complications || |
Median nerve (anterior interosseous branch)
Volkmann's ischemic contracture (compartment syndrome of the forearm)
|Late complications || |
Loss of motion
Acute vascular injuries must always be suspected in patients with supracondylar fractures. Absence of a radial pulse is common in children and, in the majority of published cases, is an indicator of brachial artery injury, even if the hand appears warm, pink, and well perfused.31 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. Treatment of supracondylar fractures with absent radial pulse begins with closed reduction and percutaneous pinning. Extremities still without a pulse despite adequate reduction warrant more aggressive vascular exploration and repair.
The most serious complication is a compartment syndrome of the forearm, also known as Volkmann's ischemic contracture. This classically occurs following a supracondylar fracture. Postischemic swelling, producing increased pressure within the enclosed osteofascial forearm compartment, reduces capillary blood perfusion below the level necessary for tissue viability. If unrelieved, the end result is muscle and nerve necrosis and eventual replacement by fibrotic tissue, producing a contracture. Refusal to open the hand in children, pain with passive extension of the fingers, and forearm tenderness are signs of impending Volkmann's ischemia. It is now well understood that the mere lack of a radial pulse does not indicate ischemia unless accompanied by these signs. Extremities with signs of ischemia are taken emergently to the operating room for fasciotomy and brachial artery exploration.
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, driving the olecranon against the humeral articular surface, separating the condyles and producing the typical fracture. Carefully search for a fracture line separating the condyles from each other and from the humerus. By definition, 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. Treatment of displaced, rotated, or comminuted fractures is often directed at reestablishing articular surface congruity. If this cannot be achieved by closed methods, then the integrity of the articular surface is restored by an open reduction and fixation. In older patients with severely comminuted injuries, elbow replacement may be considered.32 As in supracondylar fractures, admit patients with severe edema or displaced fractures.
Lateral epicondyle fractures almost never occur, because the anatomic position of the condyle reduces its exposure to direct blows, resulting instead in fractures of the lateral condyle. When they do occur, lateral epicondyle fractures are usually avulsion fractures and may be treated by long arm posterior mold, 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. Standard radiographs are obtained with special attention to any intra-articular fragment. Carefully test ulnar nerve function. Nondisplaced or minimally displaced medial epicondyle fractures can be treated nonoperatively, with early range of motion. There is an increasing trend toward operative treatment for these fractures due to significantly increased odds of bony union with fixation.33 Open fractures, unsTable joints, fragment displacement >5 mm, and an intra-articular fragment are well-described indications for surgical treatment with internal fixation. ED treatment consists of long arm posterior splint immobilization, with the forearm in flexion and pronation, and orthopedic referral.
Complications of lateral and medial epicondyle fractures are frequent and include nonunion, cubitus valgus or varus deformity, ulnar nerve palsy, and avascular necrosis.34 Careful neurovascular assessment is required for these injuries. Because surgical treatment is generally preferred, orthopedic consultation is recommended for both lateral and medial epicondyle fractures.
Lateral condyle fractures occur in children and are more common than their medial counterpart.35 Lateral condyle fractures result from a direct blow to the lateral elbow or from varus stress with the forearm extended, as in a fall on an outstretched hand. Patients complain of pain in the lateral elbow, and swelling is noted in the same area.
Medial condyle fractures are uncommon and are mostly limited to children. Mechanism of injury is from either a transmitted force from the ulna, such as a fall on an outstretched hand, or excessive valgus stress. Pain and swelling medially are 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 ossification center does not appear until age 9 to 10 years old, it is often missed on radiographs.
ED care of nondisplaced lateral and medial condyle fractures with normal neurovascular 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 neurovascular compromise require immediate orthopedic consultation. Complications include malunion with resultant cubital valgus or varus deformity, delayed ulnar nerve injury, and arthritis.
ARTICULAR SURFACE FRACTURES
Isolated trochlea fractures are rare, and they are more 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. ED treatment includes long arm posterior splint immobilization and orthopedic consultation because this is an articular surface injury and surgical repair is usually indicated. Complications are common and include limited flexion and extension, elbow joint instability, avascular necrosis, nonunion, and arthritis.
Isolated capitellum fractures are rare. They are usually associated with radial head fractures. Pain and tenderness are present over the lateral elbow, and examination reveals swelling, lateral tenderness, and limitation of flexion and extension. If pain and tenderness are present medially, then suspect injury to the medial 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 is similar to that of trochlea fractures. Definitive care is surgical, and complications are similar to those of trochlea fractures.
The distal humerus articulates with the proximal ulna to form a uniaxial hinge joint, which allows flexion and extension of the forearm and provides some intrinsic stability. The trochlea of the humerus rests in the greater sigmoid (semilunar) notch of the ulna. The anterior projection of the notch is the coronoid, and the posterior prominence, which is easily palpable, is the olecranon. The brachialis muscle inserts at the coronoid, and the triceps muscle inserts at the olecranon. Nearly all proximal ulna fractures are considered intra-articular, with the exception of a proximal olecranon chip fracture.
Coronoid fractures are usually associated with posterior elbow dislocations as the trochlea is driven into the coronoid. A coronoid fracture can rarely occur as an isolated injury secondary to elbow hyperextension.36 There is pain, swelling, and tenderness over the antecubital fossa. Radiographic visualization is best with lateral and oblique films. Often CT is needed to make the diagnosis.
ED treatment should include long arm posterior splint immobilization with the elbow in flexion and the forearm in supination, ice, elevation, analgesics, and referral to an orthopedic surgeon within 24 hours. Conservative treatment of nondisplaced coronoid fractures remains controversial, and early orthopedic referral is indicated. Displaced fractures or those associated with joint instability require open reduction and internal fixation and frequently have poor outcomes.
The olecranon is usually fractured by direct trauma or by a fall with forced hyperextension of the elbow. Olecranon fractures are quite common and represent up to 10% of upper extremity fractures.37 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, triceps function is usually compromised. It is important to test forearm extension against resistance, as the patient may falsely appear to have intact forearm extension 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 age 11 years old and fuses by age 16 years old, 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 immobilization. Nonoperative treatment may also be considered for poorly functioning elderly patients who would not tolerate surgery. All other olecranon fractures require surgical repair.38
The radial head is located just distal to the lateral epicondyle. Pronating and supinating the forearm with the elbow flexed allows the examiner to palpate the radial head. It articulates with the capitellum and the lesser sigmoid notch of the ulna to form a pivot joint. The radial head serves as a stabilizer of the elbow against valgus stress, along with the medial collateral ligament, and against longitudinal forces.
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 be driven into the capitellum. Associated injuries are common and may include capitellum, olecranon, and coronoid fractures, medial collateral ligament injury, medial epicondyle avulsion fracture secondary to valgus stress, and elbow dislocation. A specific associated injury, the Essex-Lopresti lesion, occurs when there is disruption of the triangular fibrocartilage of the wrist and the interosseous membrane between the radius and ulna, causing pain in the wrist and forearm. The result is a distal radioulnar joint dissociation, which can cause migration of the radius proximally if radial head excision is performed. Open reduction and internal fixation of the proximal radius fracture is indicated for this injury.
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. On standard elbow radiographs, radial head fractures may be subtle (Figure 270-16). Additional images, including obliques and a radial head–capitellum view, may be helpful. Furthermore, two radiographic clues can aid in the diagnosis. The first is 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. The other clue is the appearance of an abnormal fat pad (Figure 270-9).
Subtle radial head fracture and anterior fat pad sign (arrow).
Nondisplaced fractures with no mobility restrictions can be treated conservatively with immobilization. For these, ED treatment consists of sling immobilization with the elbow in flexion, ice, elevation, analgesics, and referral to an orthopedic surgeon within 1 week. Consider aspiration of the joint hematoma in the ED to improve pain and facilitate early mobilization.39 Additional pain control may be obtained with intra-articular injection of lidocaine or bupivacaine following aspiration, but this does not offer any long-term benefit over aspiration alone.40 For displaced fractures or those with restricted range of motion, surgical repair is generally indicated, and orthopedic referral within 24 hours is needed. Complications of radial head fracture include chronic pain and restricted range of motion at the elbow.