Open repair of foveal avulsion of the triangular fibrocartilage complex and comparison by types of injury mechanism.

PURPOSE: Little attention has been paid to injury mechanisms of foveal avulsion of the triangular fibrocartilage complex (TFCC). The purpose of this study was to determine whether the mechanism of injury is associated with different anatomic disruptions as well as different preoperative clinical symptoms. We also evaluated the clinical results of an open repair method for foveal avulsion according to the mechanism of injury. METHODS: Fifteen patients with a traumatic foveal TFCC avulsion were treated with an open repair technique. The injury mechanism was forced wrist extension in 10 patients (group E) and forced forearm rotation in 5 patients (group R). All patients in group E and 3 in group R showed positive fovea signs. Surgical and clinical findings were compared according to the 2 types of injury mechanism. RESULTS: Foveal insertions of TFCC were found in surgery to be disrupted in all 15 patients. In addition, disruption of the dorsal styloid insertions of the radioulnar ligament showed a significantly greater association with group R than with group E. Clinical results showed significant postoperative improvement but were marginally different between the 2 groups. CONCLUSIONS: The most common mechanism of foveal TFCC avulsions is forced wrist extension, an injury that commonly shows positive fovea signs and leaves the dorsal styloid insertion of the radioulnar ligament intact. Forced forearm rotation is the second most common injury mechanism that is more frequently associated with disruption of the dorsal styloid insertion. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.