Interposition arthroplasty versus dual cup mobility prosthesis in treatment of trapeziometacarpal joint osteoarthritis: a prospective randomized study

Background: Osteoarthritis (OA) of the trapeziometacarpal (TMC) joint is a common cause of pain and functional disability of the hand and is the second most frequent site in the hand of OA. This prospective randomized study analyses and compares the outcomes and global assessment of 2 different surgical techniques for rhizarthrosis treatment: trapeziectomy with tendon interposition arthroplasty and total joint replacement with Touch® (KeriMedical; Geneva, Switzerland) TMC prosthesis. Methods: The enrolled patients were randomly divided into 2 groups: group A included 71 patients (75 hands) treated with tendon interposition arthroplasty, while group B included 65 patients (72 hands) treated with total joint replacement. Clinical and radiological outcomes were collected before surgery and at 1, 3, 6, 12, and 24 months of follow-up. Results: Although the values of all clinical tests performed during follow-up demonstrated statistically significant improvement over preoperative ones in both groups, patients treated with prosthesis showed faster improvement, especially in tests of strength and range of motion, which showed better results than patients treated with trapeziectomy and tendon interposition arthroplasty throughout the follow-up. Conclusions: Our study suggests that joint replacement should be preferred to interposition arthroplasty as the treatment of rhizarthrosis, choosing the latter in case of prosthetic replacement complications or scaphoid-trapezium-trapezoid OA.