Biomedical subjects
Publications and source records attributed to G de Groot Swanson.
Implant arthroplasty reconstruction of the thumb basal joints can provide pain-free, stable mobility and improved strength. The complications are few and essentially retrievable. The recommended operative procedures are challenging and must be carefully executed to obtain rewarding results.
The authors present a classification of the implant materials available, the basic types of implants, their fixation and the basic methods of implant arthroplasty used in the hand and wrist.
A brief review of the possible methods of reconstruction of the arthritic MP joint including synovectomy, arthrodesis and arthroplasty with or without implant has been presented. The surgical technique for flexible hinge implant arthroplasty at the MP joint of the fingers and thumb has been detailed. A computer analysis of the results of MP joint flexible implant arthroplasty obtained in a special field clinic study have been presented.
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.
The wrist joint is frequently impaired in rheumatoid, post-traumatic, and degenerative arthritis. Stable radiocarpal motion, even limited, can improve functional hand adaptations, especially if the proximal or distal joints are disabled. A flexible silicone intramedullary stemmed hinged implant was developed in 1967 to be used as an adjunct to resection arthroplasty of the radiocarpal joint while at the same time maintaining the radiocarpal relation and allowing wrist motion in all planes. The surgical technique includes proper contracture release, bone preparation, extensor tendon repair and balancing, and dorsal and palmar capsuloligamentous repair to allow only 60 degrees of total passive flexion/extension and 10 degrees radial/ulnar deviation. This procedure can be combined with ulnar head capping. Metal bone liners (grommets) may be used to protect the radiocarpal implant from sharp bone edges. From January 1970 to April 1983, 181 wrist implant procedures had been performed in 139 patients, most of whom had rheumatoid arthritis. Stable, pain-free functional motion was obtained in the majority of cases. Roentgenograms showed the implants to be well tolerated by bone. Complications were infrequent. Because this procedure does not require cementing or significant bone resection, revision or arthrodesis procedures are facilitated.