Implant arthroplasty for metacarpal and interphalangeal joints in rheumatoid arthritis.

An ongoing research project for the development of flexible implants for small joint arthroplasty in the extremities has been carried out since 1962 by the senior author, based on the concept that a low-modulus implant would not harm bone because of its force dampening characteristics. Implants made of medical grade silicone elastomer were designed, developed and extensively tested in laboratory and clinical studies. Long term clinical, radiographic and biological studies have shown these implants to have excellent biocompatibility and biodurability. The flexible implants act as dynamic spacers to help maintain proper joint alignment and spacing, while supporting the new capsuloligamentous system that develops around them. The flexible implants act as an adjunct to resection arthroplasty to make its' results more predictable, reproducible and durable. Our long term results have shown that flexible implant resection arthroplasty can provide very good durability, range of motion, stability, pain relief, biotolerance and retrievability. The indications, contraindications, surgical techniques and postoperative rehabilitation methods will be discussed for the metacarpophalangeal and proximal interphalangeal joints.