On twenty-six cemented total hip replacements that had been followed for
an average of 10.4 years (range, nine to thirteen years), a retrospective
radiographic study was done to assess dimensional changes in the cross
section of the bone in a group of asymptomatic patients. Cortical
dimensions were measured on radiographs and were normalized using a
radiographic distortion factor that was derived from the width and length
of the prosthesis. The data were then analyzed using a least-squares
method. Analyses were performed for the men, for the women, and for the
combined group. The results for all three groups showed a significant
decrease in cortical thickness as well as widening of the medullary canal,
but no periosteal expansion.