Changes in femoral cortical dimensions after uncemented revision hip arthroplasty. Radiological results with the porous-coated bi-metric femoral stem prosthesis in 15 asymptomatic cases.

Abstract

The radiographic results of 15 uncemented femoral revisions after a minimum follow-up period of 2 years are reported. Digital imaging was used to quantify the remodeling of the cortical bone. A method using computer-assisted video densitometry was developed and radiographs were scanned and digitized by a computer. The femoral cortex in five regions, as well as the endosteal diameter, was determined. After rearthroplasty, there was a significant loss in cortical bone with widening of the medullary canal. The periosteal diameter did not change. This endosteal resorption could contribute to further aseptic loosening. In addition, it could be an explanation of the primary prosthetic failure; one mode of failure could be an accelerated rate of endosteal expansion in a subgroup of the general population after hip arthroplasty.