Epidemiology

Injury is a leading cause of mortality, morbidity, and lost days of work. The annual health care cost of injuries exceeds $9.2 billion. Traumatic injuries result in more than 34 million emergency department (ED) visits each year.¹ The highest rate of injuries occurs in persons between the ages of 15 and 24 years. Likewise, forearm fractures are commonly seen in young adults but have a bimodal distribution, with a second increased incidence in the elderly.²

Presenting Signs and Symptoms

Symptoms of forearm fractures include pain, forearm edema, forearm ecchymosis, abnormal or reduced mobility from the wrist through the elbow, and complaints of neurovascular compromise. Findings on physical examination can include obvious bony deformity; shortening of the forearm; crepitus; tenderness to palpation of the forearm; joint effusions; abnormal mobility of the wrist, forearm, or elbow; and neurologic and vascular deficits of the forearm, wrist, or hand. Box 88.1 lists the signs and symptoms of fractures and complications that indicate serious injury.

In general, forearm fractures are classified by the bone (or bones) involved, anatomic location, trajectory of the fracture and alignment of the fracture fragments, and the presence of angulation, rotation, comminution, and concurrent dislocations. All fractures should be further described as open or closed, and the presence (or absence) of distal neurologic and vascular function should be noted (Fig. 88.1).

Fig. 88.1 Approach to patients with a suspected forearm fracture.

DDX, Differential diagnosis; OR, operating room; Ortho, orthopedics.

Types of forearm fractures that are frequently mentioned in the medical literature are described in Table 88.1.

Table 88.1 Types of Forearm Fractures

Pediatric Fractures

Forearm fractures in the pediatric population include several additional entities because children have a plastic bone matrix and active growth plates, both of which contribute to unique fractures (Table 88.2). In children, when an external force bends a long bone, one side of the cortex may be disrupted while the other side remains intact (greenstick fracture). Alternatively, a deformity of the bone may occur without an obvious fracture line (plastic deformity). With compression, buckling of the cortex may be seen (torus fracture). Depending on the age of the child, fractures through the various growth plates of the elbow and wrist may also occur (Salter-Harris fractures).⁵

Table 88.2 Types of Pediatric Fractures

Differential Diagnosis and Medical Decision Making

The differential diagnosis for forearm fractures includes any soft tissue injury to the forearm, in addition to acute skin, soft tissue, and joint infections (Box 88.2). Some clinical aspects of acute arterial occlusion, as well as venous thrombosis, may mimic forearm fractures. Any acute neurologic change, including paresthesias, weakness, and functional loss, should be considered along with forearm fractures. Two normal variants sometimes mistaken for forearm fractures on radiographs are normal growth plates in children and nutrient vessels.

The orthopedic literature often recommends radiographs of a suspected fracture and additional films of the joints above and below the injury (Fig. 88.2; Table 88.3). This is true for forearm fractures if they are close to the joint (either elbow or wrist) or are suspected of having a concurrent dislocation (Fig. 88.3).

Fig. 88.2 Radiographs demonstrating the need for at least two views of a fracture.

In A (anteroposterior view), there appears to be good alignment; in B (lateral view), a large amount of displacement is obvious.

Table 88.3 Radiographs Useful in the Differential Diagnosis of Forearm Fractures

AP, Anteroposterior.

Fig. 88.3 Anteroposterior (A) and lateral (B) radiographs of a Monteggia (fracture of the ulna and dislocation of the radial head).

(Courtesy Dr. Alan Nemeth, Brookhaven Memorial Hospital Medical Center, East Patchogue, New York.)

Because isolated proximal ulnar fractures are unusual, a Monteggia fracture must be suspected and specific attention paid to the radial head to assess for dislocation. Specific radiographs of the radioulnar joint should be obtained if dislocation is suspected because the overall forearm radiograph may not reveal subtle injury. A longitudinal line through the radial shaft and head must transverse the capitellum in all views. Open reduction with internal fixation (ORIF) will probably be required, although children may be treated with casting.

Galeazzi fractures are two to three times more common than Monteggia fractures and have the potential for higher morbidity as a result of disruption of the distal radioulnar joint accompanying fracture of the distal end of the radius. Disruption of the radioulnar joint must be suspected in patients with a fracture of the ulnar styloid, shortening of the radius (5 mm), or widening of the radioulnar joint (2 mm). ORIF will probably be required.

Additional films are not usually necessary with uncomplicated shaft fractures (one bone, nondisplaced). If the fracture is intraarticular, additional radiographic views or computed tomography or magnetic resonance imaging may be suggested (Table 88.4).

Table 88.4 Special Circumstances in the Differential Diagnosis of Forearm Fractures

AP, Anteroposterior; CT, computed tomography; MRI, magnetic resonance imaging.

A Colles fracture is probably unstable if the fracture is comminuted and exhibits ulnar styloid displacement, loss of radial height of 2 mm or greater, intraarticular displacement of more than 1 mm, or dorsal angulation greater than 20 degrees.

Although most forearm fractures are evident on plain radiographs, occult fractures of the elbow may be difficult to interpret. One indication of an elbow fracture is the fat pad or sail sign, which indicates hemarthrosis of the elbow joint and thus a fracture.⁶

The fracture is probably unstable if it is comminuted.

Treatment

Prehospital treatment includes immobilization to reduce the development of further injury and help control pain. The mainstays of ED treatment include pain control, reduction of further injury, immobilization, and appropriate disposition.⁷ Pain control should include elevation of the arm and cooling via ice packs. Oral or parenteral pain medications are usually indicated, depending on the age and size of the patient and the amount of pain.

Reduction of further injury depends on the fracture. Patients with open fractures and suspected open fractures should be given early parenteral antibiotic therapy and tetanus prophylaxis (if indicated). Displaced fractures and fractures with associated dislocations require early relocation, either by the emergency physician in consultation with an orthopedic surgeon or, if the patient’s condition is unstable, by an orthopedic surgeon in the ED.⁸

The preferred method of fracture immobilization in the ED is splinting rather than casting because fracture edema will tend to increase in size over the first 24 hours. Specific splints for particular fractures are listed in Table 88.5.

Table 88.5 Immobilization of Forearm Fractures

Follow-Up, Next Steps in Care, and Patient Education

Patients with forearm fractures can be classified into three categories: those who need immobilization with routine orthopedic follow-up, those who need interventions in the ED with very close follow-up, and those who should be admitted to the hospital.⁹

Admission criteria include all open fractures, fractures with suspected compartment syndrome or neurovascular compromise, and fractures (or fracture-dislocations) that cannot be adequately reduced in the ED. Patients who have difficulty with pain control or social issues that reduce their ability to take care of their injuries may also require admission. Any suspicion of child abuse, interpersonal violence, or elder abuse may also necessitate admission.

Forearm injuries that require urgent orthopedic referral include unstable fractures, fractures that can be reduced and splinted but need further internal fixation, and dislocations that are reduced.

Forearm fractures that can be evaluated by an orthopedist in a 1-week range include stable nondisplaced fractures that show no evidence of neurovascular compromise.

Complications of fractures are due to missed injuries (a second fracture, open fracture, or fracture dislocation) and include early signs of neurovascular compromise or impending compartment syndrome. For most forearm injuries, return to full function can be anticipated.