Total hip Replacement Ad Modum Ring

Abstract

A 2–9 years (mean 5.4) follow-up of 295 Ring total hip replacements is presented. the pre-and postoperative conditions were evaluated according to Charnley. There were improvements as regards pain (1.4 to 5.4 points), mobility (2.5 to 5.0 points) and walking ability (2.2 to 4.0 points). the mortality rate was 0.3 per cent. Early deep infection occurred in 0.7 per cent and late deep infection in 0.3 per cent; 4.4 per cent needed revision for loosening (long femoral component 1.0 per cent; short femoral component 8.6 per cent). Radiological loosening indicated by a radiolucent zone of at least 3 mm wide surrounding the prosthesis was found to have no significant correlation with the clinical result. A significantly greater number of patients required reoperation when the short prosthesis was used. Even apart from those reoperated on the results were significantly poorer when the short prosthesis was used.

It is concluded that the Ring prosthesis can still be recommended, but that the long prosthesis should be used whenever possible. When this is not possible, a cemented prosthesis should, perhaps, be used.

Key Words:

• hip joint
• metal-to-metal prosthesis
• Ring total arthroplasty