Long-term follow-up of cemented total hip replacement for osteoarthritis.

Two hundred twelve total hip replacements performed as a primary procedure have been followed for more than 10 years. One hundred thirty-six hips had adequate radiographic follow-up. Mechanical loosening of the acetabular and femoral component continue to be the major postoperative complications and in this series was 24 per cent. The incidence of femoral loosening has declined, however there is a continuing increase in acetabular revisions as well as an increase in bone-cement radiolucencies in relation to the acetabular component. Analysis of mechanical and technical parameters identifies those arthroplasties at increased risk of mechanical loosening, it is necessary to have two or more parameters of poor technique present before there is an increased incidence of loosening of the femoral component. Changes in stem design and cementing techniques in the early 1980s have addressed these parameters and in the mid-term have significantly decreased the incidence of mechanical failure. However we await the 10- to 15-year follow-up of these technical improvements to assess whether they will improve longevity of a biologic procedure. It is difficult to predict failure of cemented acetabular components and with longer follow-up there appears to be a steady increase in the incidence of acetabular loosening compared with a decrease in the occurrence of femoral loosening.