Trapeziometacarpal Arthrodesis With Tendon Interposition Resection Arthroplasty at the Scaphotrapeziotrapezoid Joint for Eaton Stage IV Trapeziometacarpal Osteoarthritis.

Purpose: Trapeziectomy and proximal trapezoid excision with ligament reconstruction and tendon interposition or suspensionplasty is the standard method for the treatment of Eaton stage IV trapeziometacarpal (TMC) osteoarthritis (OA). However, these procedures have potential risks, such as residual metacarpophalangeal (MCP) hyperextension and thumb shortening. The aim of this study was to present the surgical technique and clinical results of TMC arthrodesis with tendon interposition resection arthroplasty (TIRA) at the scaphotrapeziotrapezoid joint. Methods: Thirteen hands of 10 patients with stage IV TMC OA underwent TMC arthrodesis with TIRA between 2014 and 2024, with a minimum follow-up of 12 months. Pre and postoperative visual analog scale score, quick disabilities of arm, shoulder, and hand score, patient-rated wrist evaluation score, grip strength, and side pinch strength were evaluated. Pre and postoperative radiographs were obtained to evaluate bone union, the angles of the MCP joint, and the capitolunate angle. Results: The mean visual analog scale score decreased from 77 (SD: 13) before surgery to 10 (SD: 13) at follow-up. The mean disabilities of arm, shoulder, and hand score was 46 (SD: 17) before surgery and 22 (SD: 16) at the final follow-up. The mean patient-rated wrist evaluation score was 66 (SD: 21) before surgery and 15 (SD: 17) at the final follow-up. The mean side pinch was 2.7 kg (SD: 1.1) before surgery to 4.3 kg (SD: 1.2) at the final follow-up. Bone union at the TMC joint was achieved in all cases. The mean MCP joint angle was -20° (SD: 22°) before surgery and -4° (SD: 19°) at the final follow-up. The mean capitolunate angle was 0° (SD: 13°) before surgery and -2° (SD: 8°) at the final follow-up. Conclusions: Compared with preoperative conditions, TMC arthrodesis with TIRA at the scaphotrapeziotrapezoid joint achieved satisfactory results with substantial improvement. This novel procedure could be used for stage IV TMC OA. Type of study/level of evidence: Therapeutic IV.