Niebauer trapeziometacarpal arthroplasty

A retrospective review of 22 Niebauer implant arthroplasties of the trapeziometacarpal joint for treatment of advanced osteoarthritis in 18 patients is reported. Mean follow-up was 2.4 years. Thirteen patients stated they had good pain relief, two were slightly improved, and three had no improvement. Six patients believed their functional status was improved, 10 were the same, and 2 were made worse. Thumb abduction and strength measurements were similar in the hands with operation and those without operation. Full opposition was present in 68% of thumbs with operation versus 93% of those thumbs without operation. Asymptomatic implant subluxation of 50% or less was present in 23% of thumbs. However, only 9% had symptomatic mechanical instability and these thumbs showed greater than 75% subluxation. Implant breakage and "silicone synovitis" was not evident on clinical and radiographic examination. Evaluation of the bony response around the implant stem revealed a consistently present sclerotic line. Although the design features of the Niebauer implant offer theoretical advantages for stability and fixation, this study does not demonstrate better results compared with other types of silicone trapezium implants. Therefore, a surgeon should choose this implant on the basis of a personal preference for ease of implantation and not for improved clinical results.