Review and analysis of silicone-rubber metacarpophalangeal implants.

A series of 530 consecutive arthroplasties using silicone-rubber implants in 119 patients was reviewed. Clinical and roentgenographic evaluations were completed on sixty patients and 254 implants, with an average follow-up of two and a half years; the remaining fifty-nine patients were evaluated by questionnaire. All but three patients had rheumatoid disease, usually with severe deformity, and many of the patients underwent other procedures on the upper extremity; these procedures often precluded early motion after the arthroplasties. Three prostheses (0.6 per cent) were removed because of infection, and reoperation was required in 2.4 per cent of the joints. Detailed clinical follow-up of 254 prostheses revealed the following: for Swanson prosthesis-average motion 38 degrees, fracture rate 26.2 per cent, and recurrence of clinical deformity 11.3 per cent; for Neibauer prostheses-average motion 35 degrees, fracture rate 38.2 per cent, and recurrence of clinical deformity 44.1 per cent. It should be noted that use of early implant types and some variations from the designer's recommended rehabilitation protocols were features of this series.