OTA 1997 Posters - Hand & Wrist Fractures

Occult Scaphoid Fracture: High Definition Macroradiography vs. MR Imaging

Christian Kukla, MD, Christian Gaebler, MD, Martin J. Breitenseher, MD, Vilmos Vecsei, MD, Prof.

Vienna Medical School, Vienna, Austria

Purpose: Fractures of the scaphoid are notoriously difficult to diagnose, and treatment may be very time-consuming. This prospective study was performed in order to compare the present "gold standard" of four-view plain radiography with high-definition macroradiography (HDMR) and magnetic resonance imaging (MRI) to work out the diagnostic usefulness and to discuss the economic repercussions.

Materials and Methods: Twenty-five patients with clinical signs and symptoms suggestive of scaphoid fx were studied (1.8 male: 1 female). Mean age was 30.4 years (range 14-65). Exclusion criteria: Scaphoid fx visible on the initial plain radiograph. All patients had tenderness in the anatomical snuffbox as well as axial stress tenderness on thumb manipulation. The clinical examination was followed by initial sets of scaphoid view in 4 different plains (I-SSV). Repeat sets (R-SSV) on average on Day 14 after injury followed (range 10-16). These findings were compared with those of MRI (ø day 3 after injury, range 1-6) and HDMR (ø day 2, range 1-7) as well as with those of the I-SSV (the referring traumatologist was not informed of the results of the MRI and HDMR).

Results: 25 patients seen during this study were diagnosed as having suspected scaphoid fx's. Clinical examination did not permit any associated injuries to be substantiated. I-SSV of the wrist, did not show a scaphoid fx in any of the 25 patients. R-SSV showed bony abnormalities of the scaphoid in 5 cases: 3 had a fx of the scaphoid; in the other 2 cases, there was an avulsion fx. In another 4 cases, other bony lesions were found. HDMR produced evidence of 4 cases of bony lesions, of the scaphoid: 2 patients had a fx of the scaphoid, while in the other 2 cases there was an avulsion fx of the scaphoid. In another 2 cases, other bony lesions were found. MRI showed bony abnormalities of the scaphoid 8 times: 4 patients had a fx of the scaphoid, other 4 had an avulsion fx of the scaphoid; in 3 cases, there were minor bony lesions of the distal scaphoid pole. In 5 cases, other bony lesions were found coincidentally. In another 3 cases, purely ligamentous lesions were found. A comparison of the HDMR findings with those obtained by MRI showed MRI to be superior for the detection of bony lesions and additional soft tissue injuries. HDMR was able to detect only 2 of 4 scaphoid fx's, and only 4 of 8 bony lesions of the scaphoid.

Discussion: MRI will save much of the radiation exposure and the financial costs otherwise required for numerous repeat radiographs, more than one third of the patients will have no bony lesions, and may thus be managed without casting. In the light of our experience, we would certainly recommend initial MRI, which was shown in our comparative study to have 100% sensitivity in the detection of bony lesions, in order to effect a marked reduction in the time off work of patients whose MRI scans show a normal scaphoid bone pattern.