Wrist stability after experimental traumatic triangular fibrocartilage complex lesions

PURPOSE: The aim of this study was to evaluate changes in stability of the wrist after experimental traumatic triangular fibrocartilage complex lesions. METHODS: Sixteen cadaver wrist specimens were included: 8 were fixed in neutral rotation of the forearm, 4 in maximal supination, and 4 in maximal pronation. The specimens were tested in a multiangle and torque measuring instrument. First the intact specimen was tested, second a dorsal arthrotomy was performed, and the third test was with 1 of 4 different experimental lesions according to Palmer's classification of traumatic triangular fibrocartilage complex lesions (1A-1D). Forced radioulnar deviation and internal/external rotation were recorded with a load of 0.75 Nm in the interval -60 degrees to +60 degrees of flexion. RESULTS: We found the 1C lesion to be highly significantly related to wrist stability. Forced radioulnar deviation and forced internal/external rotation were altered significantly in 35 degrees of wrist extension. The other lesions did not alter the stability of the wrist significantly and the rotation of the forearm had no influence on the outcome. CONCLUSIONS: The 1A lesion does not alter significantly wrist stability and hence the common treatment by a two-third excision of the central part of the disk will not affect wrist stability. A 1C lesion alters significantly the stability of the wrist. At 35 degrees of wrist extension forced radioulnar deviation and forced internal/external rotation were altered significantly; this might be used in a clinical test for a 1C lesion. The rotation of the forearm has no influence on the outcome.