Forearm Fractures in Emergency Medicine Workup

Updated: May 09, 2016
  • Author: Toluwumi Jegede, MD; Chief Editor: Trevor John Mills, MD, MPH  more...
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Workup

Imaging Studies

General radiography principles

Anteroposterior and lateral views of the wrist, forearm, and elbow are required when forearm fracture is suspected from clinical findings.

Forearm radiographs, which include distal joints, are inadequate for absolutely excluding associated wrist and elbow injuries, as diagnosis of radioulnar dislocation requires the x-ray beam to be centered at the joint.

Nightstick fracture

Defined as an isolated midshaft ulnar fracture, usually as a result of the forearm being held in protection across the face. It can also occur with excessive supination or pronation. These require orthopedic referral and can be immobilized with a long-arm splint with 90 degrees of elbow flexion and the hand in a neutral position. Some authors advocate that after 1 week the splint or cast be replaced by a prefabricated functional brace, which allows better wrist mobility and return to function. [9] Open reduction and internal fixation (ORIF) becomes necessary when displacement greater than 5 mm or angulation greater than 10º persists.

A systematic review of published randomised, controlled trials and observational studies that assessed the outcome of nightstick fractures after above- or below-elbow immobilization, bracing, and early mobilization found that early mobilization was associated with the shortest radiologic time to union (mean, 8.0 weeks) and the lowest mean rate of nonunion (0.6%). Fractures that were treated with above-elbow immobilization, below-elbow immobilization, or bracing had longer mean radiologic times to union (9.2 weeks, 9.2 weeks, and 8.7 weeks, respectively) and higher mean rates of nonunion (3.8%, 2.1%, and 0.8%, respectively). [10]

Monteggia fracture

Monteggia fracture is defined as a fracture of the ulna (usually proximal one third) with dislocation of the radial head. Anterior radial head dislocation is most common (60%), yet medial, lateral, and posterior dislocations also occur. Isolated proximal ulnar fractures are rare. Always suspect a Monteggia fracture/dislocation, and closely examine radial head for dislocation or other evidence of injury.

Radial head dislocation can be missed when radiographs are misinterpreted, falsely negative, or inadequate. It also may go unrecognized when the dislocation reduces spontaneously prior to imaging. A line drawn through the radial shaft and head must align with the capitellum in all views to exclude dislocation.

Immobilize with a long-arm splint (with elbow flexed 90° and forearm neutral). Children may be treated by reduction and casting, while adults require admission for ORIF.

One study assessed the efficacy of the following treatment strategy for Monteggia fracture based on the ulnar fracture pattern: closed reduction for plastic/greenstick fractures; intramedullary pin fixation for transverse/short oblique fractures; and open reduction and internal fixation for long oblique/comminuted fractures. According to the authors, none of the 57 patients treated according to the strategy experienced failure. However, 6 of 32 patients who were treated less rigorously demonstrated recurrent radiocapitellar instability (3 patients), loss of ulnar fracture reduction requiring revision surgery (2 patients), or both events (1 patient). All treatment failures occurred in complete fractures treated nonoperatively. [11]

Galeazzi fracture

Galeazzi fracture is defined as a fracture of the distal one third of the radius with dislocation of the distal radioulnar joint (DRUJ). It is also known as a reverse Monteggia fracture. Galeazzi fracture is 3 times more common than Monteggia lesion. Disruption of the DRUJ when overlooked results in a higher rate of morbidity.

Shortening of the radius by 5 mm, fracture of the base of the ulnar styloid, widening of DRUJ space by 2 mm, or subluxation of DRUJ all are associated with DRUJ pathology. Obtaining comparison views of the uninjured wrist may be helpful. A 10-20° rotation from normal radiographic position may give false-negative or false-positive readings for DRUJ dislocation. Immobilize with a long-arm splint (with elbow flexed 90° and forearm pronated). Treatment requires admission for an ORIF.

Concomitant radius and ulna fractures

Concomitant fractures usually result from a significant force applied directly to the forearm or major multisystem trauma. Swelling and deformity indicate the diagnosis, and radiographic confirmation is usually straightforward. Compartment syndrome is a potential complication because of the degree of tissue injury and swelling involved. Treatment usually requires admission for an urgent ORIF, though in children younger than 10 years, if reduced to less than 10° of angulation, these fractures may be treated by casting alone. See the image below.

Fractures of the radius and ulna with dorsal angul Fractures of the radius and ulna with dorsal angulation of distal fragments.

Essex-Lopresti fracture

Essex-Lopresti fracture is defined as a fracture of the radial head and dislocation of DRUJ, with partial or complete disruption of the radioulnar interosseous membrane.

Torus (greenstick) fracture

Torus fracture occurs in children with only a moderate degree of trauma and can be managed with a long-arm cast for 4-6 weeks when angulation is less than 10°. All require orthopedic referral. See the images below.

Torus fracture of the radius. Torus fracture of the radius.
Torus fracture of the radius. Torus fracture of the radius.