Metacarpophalangeal joint arthroplasty in rheumatoid arthritis: results of Swanson implants and digital joint operative arthroplasty.
We discuss 69 metacarpophalangeal (MP) implant arthroplasties performed in 30 patients with rheumatoid arthritis. The follow-up averaged 5 years. We studied 19 finger joint prostheses by Condamine, digital joint operative arthroplasty (stabilized version; DJOA) and 50 flexible silicone Swanson implants. We used a new comprehensive scoring system to evaluate the MP alloarthroplasties. Such a scoring system incorporates clinical and radiological data. The outcome following MP joint replacement with DJOA was never evaluated as 'good'; in 11 joints the result was 'fair', and in 8 joints, 'poor'. As regards MP arthroplasty with Swanson implants, the results were evaluated as 'good' in 40 joints, as 'fair' in 10 joints, and in none as 'poor'. In our series, DJOA did not provide stability in arthritic MP joints. In all joints replaced with DJOA, dislocation of the articulating surfaces and signs of loosening were present. We regard three factors as being the main causes contributing to the poor outcome of DJOA when used as MP replacements. Firstly, the proximal prosthetic component is poorly matched to the anatomical shape of the metacarpal bone (conisation of the bone). Secondly, adequate coaptation cannot be achieved with this prosthetic design, even in the presence of extensive soft-tissue reconstruction. Thirdly, the use of polyethylene in MP joint replacements is questionable. In contrast, the silicone Swanson implants in our series provided superior results when used as MP implants in the rheumatoid hand.
Abteilung für Rheumaorthopädie, Orthopädische Universitätsklinik Frankfurt, Frankfurt am Main, Germany.
M
M
Rittmeister
M
M
Porsch
M
M
Starker
F
F
Kerschbaumer
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008662:Metacarpophalangeal Joint / Q000601:surgery*; D008875:Middle Aged; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D016896:Treatment Outcome