RESULTS OF UNCEMENTED POROUS-COATED ANATOMIC TOTAL HIP-REPLACEMENT

We reviewed a consecutive series of 241 uncemented, porous-coated anat omic (PCA) hip replacements at an average follow-up of five years (2 t o 9). Of these, 32 had failed (13%), 26 at the acetabular component (1 1%) and six at the femoral component (2%). Acetabular failure was asso ciated with local osteolysis and excessive polyethylene wear in 20 cas es: in these histological examination showed giant macrophages incorpo rating numerous particles of high-density polyethylene. The femoral fa ilures were related to a poor intramedullary fit with subsequent subsi dence. Using the recommendation for revision as the end point, the cum ulative survival rate for prostheses was 91% at six years (95% CI +/- 6%), 73% (+/- 11%) at seven years, and 57% (+/- 20%) at eight years. T he result of uncemented PCA hip replacement is satisfactory up to six years, but then increasing failure of the acetabular component appears to be due to polyethylene wear, leading to osteolysis, loosening and component migration. At first, failure is often asymptomatic; routine follow-up of uncemented hip replacements is essential, especially afte r five years.