Simultaneous Dual Prosthetic Replacement of Trapeziometacarpal and Scaphotrapezial-Trapezoid Joints in Pantrapezial Osteoarthritis: Midterm Results of a Combined Implant Strategy.

PURPOSE: Pantrapezial osteoarthritis affects the trapeziometacarpal (TMC) and scaphotrapezial-trapezoid (STT) joints, causing pain, functional loss, and sometimes necessitating surgery. Among the various reconstructive options available for pantrapezial osteoarthritis, trapeziectomy and ligament reconstruction with tendon interposition have consistently yielded favorable long-term outcomes in many series. However, implant arthroplasty remains a valuable alternative for selected patients. This study evaluated a dual-prosthesis approach designed to preserve carpal stability and optimize thumb function.

METHODS

This retrospective study included 41 patients with advanced pantrapezial osteoarthritis who underwent simultaneous TMC and STT prosthesis implantation. Functional outcomes were assessed using grip strength, pinch (tip and key), strength, range of motion, and the Kapandji score. Patient-reported outcomes were measured using the QuickDASH and Patient-Rated Wrist Evaluation scores. Complications and revision rates were documented.

RESULTS

The mean follow-up period was 48 months. Grip strength reached 95% of the contralateral side; tip and key pinch strengths reached 100%, with no decline over time. Range of motion and Kapandji scores improved significantly from preoperative values. High patient-reported outcome scores were recorded (QuickDASH 9; Patient-Rated Wrist Evaluation 9), indicating satisfactory recovery in terms of hand use and pain. No instability was observed, and the complication rate was low.

CONCLUSIONS

Simultaneous TMC and STT prosthesis implantation offers a possibly promising solution for pantrapezial osteoarthritis, overcoming biomechanical limitations of prior techniques. By preserving carpal stability and thumb function, this approach achieves favorable functional outcomes and a low complication rate, making it a potentially superior alternative for patients with high functional demands or those requiring durable long-term results.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.