title: Midcarpal instability following malunion of a fracture of the distal radius. A case report.
abstract: The authors report a case of midcarpal instability following a malunited fracture of the distal radius. After corrective osteotomy of the radius the wrist became stable and the symptoms were completely relieved. The instability in such cases is due to subluxation of the capitate on the lunate with the wrist in radial abduction. This in turn is due to a reversal of the normal palmar tilt of the articular surface of the radius. In the mechanics of the normal wrist this palmar tilt allows the lunate to slide forwards during radial abduction, so enabling the capitate to maintain collinearity with the vertical axis of the radius. This situation can be restored by corrective osteotomy, as in the present case, with complete relief of symptoms.
mesh_terms: D000328:Adult; D006801:Humans; D007593:Joint Instability / Q000209:etiology*; D008297:Male; D010027:Osteotomy; D011884:Radius / Q000601:surgery; D011885:Radius Fractures / Q000150:complications* / Q000601:surgery; D014955:Wrist Joint