Ulnar and Radial Shaft Fractures

ByDanielle Campagne, MD, University of California, San Francisco
Reviewed/Revised Dec 2022
View Patient Education

Ulnar and radial shaft fractures frequently result from direct trauma to the radius or ulna. Concomitant dislocations are possible.

(See also Overview of Fractures.)

Fractures of the radius and ulna are frequently caused by direct blows to the forearm (eg, during contact sports, falls, or defensive actions during an assault). Concomitant dislocations can result from forces transmitted via the interosseous membrane between the radius and ulna.

Pearls & Pitfalls

  • With proximal ulnar fractures, always look for an associated radial head dislocation.

Isolated midshaft radius or midshaft ulna fractures are common.

Monteggia fractures are proximal ulnar fractures with a radial head dislocation.

Galeazzi fractures are distal radial shaft fractures with a dislocation of the distal radioulnar joint.

Symptoms and Signs of Ulnar and Radial Shaft Fractures

Radial and ulnar shaft fractures can cause pain, deformity, ecchymosis, and swelling at the site of injury.

Diagnosis of Ulnar and Radial Shaft Fractures

  • Anteroposterior and lateral x-rays

Radial and ulnar shaft fractures are generally diagnosed with anteroposterior and lateral x-rays. If a fracture is suspected, the elbow and wrist should also be examined and, when appropriate, x-rayed.

The radial head dislocation is easy to overlook in Monteggia fractures because the fracture is so obvious and should be specifically considered if a proximal ulnar fracture is identified. The radial head is typically visible outside of its normal articulation with the capitellum (capitulum). In Monteggia fractures, the radiocapitellar line also is not aligned correctly, suggesting dislocation (see figure Anterior humeral line and radiocapitellar line). In Galeazzi fractures (similar to Monteggia fractures), the distal radioulnar dislocation is easy to overlook with distal radial shaft fractures and should be specifically considered.

Monteggia Fracture Dislocation (1)
Hide Details
This x-ray shows proximal ulnar fracture (blue arrow) with associated radial head dislocation. The radial head (red arrow) is above the capitellum, its normal articulation.
Image courtesy of Danielle Campagne, MD.
Monteggia Fracture Dislocation (2)
Hide Details
This x-ray shows proximal ulnar fracture with concomitant radial head dislocation (red arrow).
Image courtesy of Danielle Campagne, MD.
Galeazzi Fracture
Hide Details
This x-ray shows a fracture of the distal radius (blue arrow) and disruption of the distal radioulnar joint (red arrow). The articular surfaces of the distal ulna and distal radius are not aligned with each other.
Image courtesy of Danielle Campagne, MD.

Treatment of Ulnar and Radial Shaft Fractures

  • For isolated radial and ulnar shaft fractures, closed reduction and splinting with outpatient orthopedic followup

  • For Monteggia and Galeazzi injuries, urgent orthopedic consultation and usually open reduction with internal fixation (ORIF)

Most isolated radial and ulnar shaft fractures can be treated with closed reduction and splinting with subsequent orthopedic referral.

For Monteggia and Galeazzi fractures, urgent orthopedic consultation is required, and ORIF is usually necessary to maintain alignment.

Key Points

  • Radial and ulnar fractures commonly result from direct forces to the forearm.

  • Take anteroposterior and lateral x-rays.

  • For isolated midshaft radial or ulnar fractures, always consider concomitant dislocations involving the wrist and elbow.

  • Treat with closed reduction and consult orthopedics.

quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID