Teaching Case

Fall on outstretched hand, negative initial x-ray, diagnosed at MRI

Fall on outstreched wrist and hand. Clinical pain and tenderness in the anatomical snuffbox were present and the patient had normal radiographs of the wrist and carpal bones, including oblique-view scaphoid radiographs with dorsal extension and ulnar duction of the wrist. Fracture diagnosed at MRI 5 days after trauma, and confirmed at follow-up x-ray 3 months later.

More than 16 % of the scaphoid fractures are not visible on the initial plain radiographs and the frequency of false positive clinical diagnosis range from 25-100 percent (ref #3). In clinical suspicion of a scaphoid fracture with normal radiographs, the recent state of the art recommended cast immobilization, and a new clinical and radiological control after 10-14 days, because an occult scaphoid fracture might take up to 6 weeks to become visible on plain radiograph To prevent unnecessary immobilization, magnetic resonance imaging, has been reported to be superior to other modalities, in diagnosing fractures of the carpal bones (ref #2). Several institutions now recommend an immediately MR imaging in patients with unclear symptomatology at the wrist.