A radiographic analysis of 166 Charnley-Müller total hip arthroplasties.

A review of 166 total hip arthroplasties, with follow-up from six months to 11 years, showed a 73% incidence of femoral "looseness," 22% incidence of progressive femoral "loosening" and 95% incidence of acetabular "looseness" for all radiolucent line sizes. Part of the reason for the high incidence of femoral "looseness" may be explained by the rigorous criteria in the authors' definition of "looseness." However, femoral "looseness" remains high at 47% and 36% incidences at the cement-bone and cement-stem interfaces, respectively, for radiolucent lines greater than 1 mm. Only one trochanteric osteotomy was performed and it is suggested that omission of trochanteric osteotomy results in inadequate cement filling of the femoral stem, as well as a lack of proper placement of the stem, contributing to the high incidence of femoral "looseness." Larger and more tapered stems, with routine trochanteric osteotomy, together with the use of low viscosity cement under pressure, should be investigated to reduce the incidence of femoral "loosening" and necessity for revision. The Harris Hip rating was found to have good correlation with the radiologic findings of loose and nonloose femoral stems.