Treatment of scaphotrapeziotrapezoid osteoarthritis with the Pyrocardan implant: Results with a minimum follow-up of 2 years.

The aim of this study was to report the results of arthroplasty using a mobile pyrocarbon implant (Pyrocardan) for isolated scaphotrapeziotrapezoid (STT) osteoarthritis. The hypothesis was that this arthroplasty leads to functional improvement without carpal instability. Twenty patients (22 implants) were included with a minimum follow-up of 2 years and an average age of 59.6 years. Outcome criteria were pain (VAS scale), QuickDASH and PRWE scores, strength (grip and pinch), wrist mobility, the Kapandji index, carpal height and the capitolunar angle measured on X-rays. The preoperative data was compared to the postoperative data. The average follow-up was 3.8 years. There was a significant improvement in pain, clinical scores and pinch strength. In terms of range of motion, we found that amplitudes were maintained except for a significant decrease in wrist extension. X-rays did not show any carpal instability; carpal height was maintained and the capitolunar angle was significantly improved. No implant dislocation was reported. The good functional and radiographic outcomes, and the absence of surgical complications are evidence that the Pyrocardan resurfacing implant is a valid option for treating STT osteoarthritis. If this arthroplasty procedure fails, another procedure can still be done. However, a long-term assessment of this technique is still needed.