Abstract
Introduction: Wrist injuries are common presentations at Accidents and Emergencies. Distal radius fractures are by far the most common. Scaphoid injuries constitute about 60% of carpal injuries. 35% occult wrist fractures are undiagnosed on 2nd visit radiography (50% distal radius/ulna). Moreover 30% patients with significant soft tissue injuries not diagnosed.
Aim: To compare the MRI (magnetic resonance imaging) and bone scans in the diagnosis of X-Ray negative wrist injuries. To functionally score these wrist at the end of 1-year to assess the outcome.
Materials and methods: A prospective study was done in 33 wrists that did not have a fracture wrist detectable on plain X-ray. The MRI and bone scan were done on the same day within 5-7 days after the injury. PD Fat Saturation Axial and Coronal images were undertaken with MRI. Clinical scoring was done after 1 year after the injury to assess the outcome of these injuries.
Results: We detected fractures in 10 wrists on bone scans and 8 fractures on MRI scans. There was a correlation between MRI and bone scan in 5 Cases. We noted 9% (3/33) of false positive cases with bone scan. Bone scans correlated with the site of injury in 10% of cases. 1 fracture was missed in both MRI and bone scan. MRI identified 4 significant soft tissue injuries and capsular edema in 29/33 cases, which were not identified on bone scans. MRI findings showed superior correlation than bone scans with clinical findings on re-examination, which was done following the scans. PRWE (patient rated wrist evaluation) was used to score the outcome of the wrists at the end of 1 year. The patients who had soft tissue or bony damage detected on MRI had significantly higher scores at 1 year of follow-up.
Conclusion: Though bone scan has high sensitivity in diagnosis of fracture, significant soft tissue injuries will be missed. On the other hand, MRI had a high sensitivity and specificity in diagnosis of a fracture and soft tissue injuries. MRI can differentiate between a bone edema and a fracture. MRI has a disadvantage of limited exposure. Clinicians must be aware of the limitations of both investigations. Though majority of these injuries do not active intervention apart from plaster or splinting, detection of these injuries is essential to prognosticate the outcome.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
