Abstract
This report presents the long-term (over 15 years) results of four Japanese patients who underwent total joint replacement for thumb carpometacarpal (CMC) joint arthritis. Four patients (mean age 60.5 years) underwent prosthesis replacement for thumb CMC joint arthritis with AVANTA(TM) (Small Bone Innovations, Morrisville, PA, USA) implants between 2001 and 2004, with a mean follow-up of 20 years and seven months. One patient was classified as Eaton stage 2 and three patients were classified as Eaton stage 3 prior to surgery. Although radiographs at the last follow-up showed loosening of the trapezium-side implant in all cases, three of the patients were excellent and only one was good according to Eaton's clinical criteria, and none of them reported severe pain or significant problems. Despite radiographic evidence of implant loosening and subsidence, long-term results were positive with minimal clinical symptoms. The results suggest that thumb CMC joint arthroplasty can provide satisfactory long-term results. However, the use of thumb CMC joint prostheses is currently limited in Japan, and alternative surgical methods such as suspension arthroplasty are more common. We believe that the thumb CMC joint prosthesis is as effective as any other surgical method based on the good results we have seen.