Wrist Fracture in Emergency Medicine Workup

Updated: Feb 14, 2015
  • Author: Bryan C Hoynak, MD, FACEP, FAAEM; Chief Editor: Trevor John Mills, MD, MPH  more...
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Workup

Imaging Studies

Routine radiographs of the wrist include AP, lateral, and oblique views. These are adequate to identify most fractures. Look for evidence of displacement of carpal bone fractures because this often indicates the need for operative intervention.

When evaluating a fracture of the distal radius or ulna, carefully check the normal anatomic alignments. The radiocarpal joint viewed on the lateral film normally has 11° of palmar angulation with a range of 1-23°. Ulnar angulation on the AP film is normally 15-30°. The radial length, which is the distance between the ulnar aspect of the distal radius and the tip of the radial styloid, normally measures 11-12 mm.

Look for an associated ulnar styloid fracture and involvement of the radiocarpal joint or DRUJ. If the radius appears to be angulated and/or displaced significantly, maintain a high degree of suspicion for a concomitant fracture of the ulna.

Scaphoid fractures often are not seen on routine radiographs. Scaphoid views taken with the wrist deviated toward the ulna and slightly supinated may help to demonstrate a fracture. The approximately 10-15% of fractures that are occult may be apparent on plain films after 10-14 days as bony reabsorption occurs at the fracture site. While not appropriate for ED workups, CT scans and bone scans as early as 3 days after injury may aid in the diagnosis.

Bone scan or MRI may be necessary to detect occult fractures not visualized on plain radiographs. MRI is superior to repeat radiographs for detecting occult scaphoid fracture [5] and is the criterion standard for detecting scaphoid fractures, with a sensitivity of 95-100% and specificity approaching 100%. [6, 7, 8]

In a systematic review of 75 studies, MRI was determined to be the most accurate imaging test to diagnose scaphoid fractures in ED patients with no evidence of fracture on initial x-rays. If MRI was unavailable, CT was adequate to rule in scaphoid fractures but inadequate for ruling out scaphoid fractures. Both MRI and CT shared the added benefit of identifying alternative etiologies for posttraumatic wrist pain. Scaphoid fractures are the most common carpal fracture, representing 70% of carpal bone fractures. [9]

In 124 patients who had wrist trauma and displayed typical clinical symptoms suspicious of an acute scaphoid fracture, multidetector computed tomography (MDCT) was shown to be superior to radiography. Conventional radiography detected 34 acute fractures of the scaphoid, whereas MDCT revealed a total of 42 scaphoid fractures. [10]

Injuries to the hamate and trapezium can be visualized best with a carpal tunnel view.

Like scaphoid injuries, injuries to the lunate and capitate may not be well visualized on plain films, and CT scan may be required.