A technique was developed to determine the wear of the acetabular
component of a total hip replacement by examination of standardized initial
and follow-up radiographs. Three hundred and eighty-five hips were followed
for at least 9.5 years after replacement. The least amount and rate of
linear wear were associated with use of a femoral head that had a diameter
of twenty-eight millimeters (p less than 0.001). The greatest amount and
mean rate of linear wear occurred with twenty-two-millimeter components,
but these differences were not statistically significant. The greatest
volumetric wear and mean rate rate of volumetric wear were seen with
thirty-two-millimeter components (p less than 0.001). A wider radiolucent
line in acetabular Zone 1 was associated with use of the
thirty-two-millimeter head. The amounts of resorption of the proximal part
of the femoral neck and of lysis of the proximal part of the femur both
correlated positively with the extent of linear and volumetric wear; this
suggests an association between the amount of debris from wear and these
changes in the femoral neck and proximal part of the femur.