Outcomes of MAÏA® dual mobility CMC joint arthroplasty – with short to medium term outcomes

Introduction: There is no consensus on the ideal surgical intervention for trapeziometacarpal joint arthritis. Although trapeziectomy has been the preferred procedure for several decades, trapeziometacarpal joint replacement has been gaining favour over several years owing to improvements in implant design. Dual mobility implants have been introduced to reduce the risk of dislocation associated with earlier single mobility versions. The aim of this study was to report the medium-term clinical outcomes of trapeziometacarpal joint replacement using the MAÏA ® dual mobility implant, from a single tertiary referral centre. Methods: This study included 106 patients with trapeziometacarpal joint osteoarthritis who received MAÏA ® dual mobility implants between 2017 and 2023. Patients were selected based on clinical and radiological criteria, with exclusions for inflammatory arthritis and STT joint involvement. Outcomes were assessed pre- and postoperatively using validated clinical scores, grip strength and radiographs at set intervals. Results: Patients were followed for an average of 53 months (IQR 20 to 58 months). The Brief Michigan score improved from 42 to 83, the pain score improved from 7 to 1, pinch strength improved from 2 to 4 kg and power grip improved from 14 to 22 kg. Two cups were revised owing to symptomatic loosening, while an additional two cups exhibited loosening but were not revised as both patients were asymptomatic. There were two intraoperative trapezium fractures. Survivorship of implants with maximum final follow-up of 6 years was 97% (IQR 20 to 58 months). Conclusions: The MAÏA ® dual mobility implant shows good improvement in pain, strength, mobility, and patient reported outcomes over the medium term, with no dislocations. Level of evidence: Therapeutic IV