High frequency failure of the Moje thumb carpometacarpal joint arthroplasty.

Arthroplasty is one of several options for treating symptomatic osteoarthritis of the thumb carpometacarpal joint. There are various hemi- and total arthroplasties available on the market. We report our experience of treating 12 patients with the Moje Acamo CMC1 prosthesis. We reviewed all the patients at a mean of 50 months postoperatively. All patients presented with loosening, migration or tilting of one or both implant components. Nine patients were symptomatic enough to warrant revision surgery with removal of the implant leaving a pseudarthrosis. At the last follow-up, five patients (42%) had already received revision surgery. All patients still possessing an implant showed progressive signs of implant loosening, although some of them had no symptoms. In order to assess their overall disadvantage compared with patients treated by primary trapeziectomy, the outcomes of these two groups were compared (matched pairs). The outcomes after revision surgery were comparable with those of primary trapeziectomy. We no longer use the Moje Acamo CMC1 implant and recommend that patients who have received this implant should be monitored carefully both clinically and radiologically.