[Total hip arthroplasty after femoral neck fractures. Results from the national registry on joint prostheses].

From September 1987 to January 1994, data on 3,876 total hip arthroplasties performed because of previous hip fracture were collected in the Norwegian arthroplasty register. During the same period, 19,654 patients received total hip arthroplasties because of osteoarthrosis. The results of total hip arthroplasties after an earlier hip fracture were compared with prostheses in patients who were operated on because of primary osteoarthrosis. After five years the cumulative percentage failure was 4.1 in the fracture group and 3.7 in the arthrosis group (p = 0.19). After adjustment for differences in sex and age distribution in the Cox model, the fracture patients were shown to have 1.35 times higher risk of revision when compared with the osteoarthrosis patients (p = 0.008). The reasons for reoperation differed, however, in the two groups. More of the fracture patients than of the osteoarthrosis patients had to be reoperated because of dislocation or femoral shaft fracture, while fewer needed reoperation because the acetabular component had loosened.