gms | German Medical Science

Objectives/Interrogation: The gold standard operative procedure for treatment of thumb basal joint osteoarthritis is to perform a trapeziectomy. For OA at other sites, joint replacement is now the treatment of choice.

Benefits of prosthetic replacement in the thumb have been overlooked due to fear of risk of dislocation, infection or implant failure. Advantages of prosthetic joint replacement surgery include comparable functional outcome, preserving range of motion and providing stability.

The aim of the study was to evaluate the advantages following trapezio-metacarpal joint replacement with an uncemented prosthesis, for patients beyond conservative treatment with splints or injections.

Methods: Over a 5 year period thumb CMCJ arthroplasty was evaluated in 150 patients using the ARPE prosthesis (Biomet), via a volar approach, in a NHS hospital by a single surgeon. Outcomes were measured using clinical and radiological assessment, with the use of functional scores and patient questionnaires. Follow up was conducted over a minimum of 2 years.

A similar cohort of patients who underwent a trapeziectomy were used as a control for comparison to gold standard treatment. All patients underwent a 6 week rehabilitation protocol with splinting and hand therapy.

Results and Conclusions: Both treatments resulted in significant improvements in functional scores. When matching patients according to pre-operative function, patients receiving ARPE arthroplasty had better post-operative function (Quick DASH). More patients receiving the ARPE arthroplasty were satisfied with their treatment and would have the same treatment again. The ARPE also resulted in less thumb shortening. It is associated with a higher complication rate (6% dislocation), but implant survival was 95%.

The majority requiring further surgery presented at initial follow-up within 2 weeks. Most reported an incident which may have predisposed to dislocation. All these patients underwent early surgery to relocate the prosthesis and the majority had a favourable outcome at 3 months.

There were no reported infections and the volar approach avoided any injury to the superficial radial nerve.

Trapezio-metacarpal arthroplasty is an effective treatment option for thumb CMCJ osteoarthritis. Arthroplasty may offer potential advantages in terms of post-operative function and patient satisfaction. The results allay the risk of complications, although requirement for further surgery is greater and must be carefully considered during patient selection and pre-operative counselling.