Efficacy of Dorsoradial Capsulodesis for Trapeziometacarpal Joint Instability: A Cadaver Study.

PURPOSE: To test the biomechanical properties of the dorsoradial capsulodesis procedure. METHODS: Six cadaveric hands were used. After exposing the trapeziometacarpal (TMC) joint, we placed Kirschner wires in the distal radius and thumb metacarpal. The rotation shear test was then performed to test the joint axial laxity, and angular measurements using Kirschner wires as reference points were documented. The dorsoradial (DR) ligament and capsule were released, followed by the intermetacarpal (IM) ligament; angular measurements were obtained. Finally, the DR capsulodesis procedure was performed, and final measurements were obtained. Comparisons were made among the various stages of ligament integrity to determine the amount of stability provided by DR capsulodesis. RESULTS: All cadavers demonstrated axial laxity with transection of the DR ligament; an increase in stability was obtained after DR capsulodesis. Transection of the capsule and IM ligament caused increased laxity relative to the native joint (median, 24° and 35°, respectively, on rotational testing). After we performed DR capsulodesis, rotational stability improved by a median of 41° compared with DR ligament transection, 49° compared with DR and IM ligament transection, and 18° relative to the native joint. CONCLUSIONS: Dorsoradial capsulodesis restores rotational stability for TMC joint after division of the DR and IM ligaments. The stability achieved was statistically significant compared with both an intact native TMC joint and induced laxity of the TMC joint. CLINICAL RELEVANCE: The DR capsulodesis procedure may improve rotational stability to the TMC joint.

Carpometacarpal Fracture-Dislocations: A Retrospective Review of Injury Characteristics and Radiographic Outcomes.

Background: The purpose of this study was to evaluate the demographics and early radiographic treatment outcome of patients with carpometacarpal (CMC) injuries at our institution over a 10-year period. Methods: We conducted a retrospective review of all patients who sustained CMC injuries of the second to fifth digits between 2005 and 2015. We recorded demographic data, mechanisms of and associated injuries, treatment methods, and complications. Injury and intraoperative and postoperative radiographs were evaluated, and the adequacy of reduction was determined on lateral radiographs of the hand using a grading system that we developed. Results: Eighty patients were included in this study. Delivering a blow with a closed fist was the most common mechanism of injury; however, high-energy mechanisms also made up a large percentage of those included. Injuries to the fourth and fifth CMC joints were most common, and these were frequently associated with fractures of the metacarpal bases and distal carpal row. Closed reduction and percutaneous pinning offered a higher percentage of patients with concentric reduction at the time of pin removal. Time to surgery was significantly different between those with concentric reduction and those with residual subluxation. Conclusion: The most common mechanism of CMC injuries was blow with a closed fist; however, these injuries can be associated with high-energy mechanisms. Fractures of the metacarpal base and distal carpal row are commonly seen with these injuries. With early diagnosis, closed reduction and percutaneous pinning achieved concentric radiographic reduction. Delayed diagnosis makes closed reduction difficult and was associated with less favorable radiographic outcome.