AB151. SOH25_AB_235. Short-term follow-up of dual mobility trapezium-metacarpal (TMC) arthroplasty: first 45 cases

Background: Carpometacarpal joint of the thumb (CMC-1) osteoarthritis is a common cause of chronic thumb pain, with an age-adjusted prevalence of 7% for men and 15% for women. It often prompts medical attention due to its significant impact on quality of life. Two standard surgical treatment options include trapeziectomy and trapezium-metacarpal (TMC) arthroplasty. Trapeziectomy, with or without ligament reconstruction and tendon interposition, has long been the gold standard surgical treatment, offering good pain relief but with reduced strength, mobility and longer recovery compared to TMC arthroplasty. This study aims to follow up on short-term outcomes and implant survival of dual mobility TMC arthroplasty.

Methods: A retrospective case series analysis was conducted of the first 45 procedures performed by a fellowship-trained hand surgeon at an Irish orthopaedic hospital. All cases had Eaton Littler grade 2 or 3 osteoarthritis. Learning curve metrics were collected on patient-reported outcome measures (PROMs), range of motion (ROM), pinch strength, revision, and complication rates. These outcomes were assessed preoperatively, 2 weeks, 6 weeks, 3 months and 1 year postoperatively.

Results: Among the 45 cases performed, in total 2 patients (4.4%) required revision due to early failure. The remaining 43 patients (95.6%) demonstrated good functional outcomes with steady improvement from the preoperative period through follow-ups.

Conclusions: In conclusion, early results show a <5% implant failure and good functional outcomes, highlighting TMC arthroplasty as an effective and valuable treatment option for CMC-1 osteoarthritis. Further follow-up is required.

Keywords: Carpometacarpal joint osteoarthritis; learning curve; surgical outcomes; thumb pain; trapezium-metacarpal arthroplasty (TMC arthroplasty)