The Uncemented CLS Expansion Cup as a Component of a Hybrid System in Primary Total Hip Arthroplasty: A Prospective Study

The purpose of this prospective study is to present the results of 160 primary total hip replacements in 145 patients with a hybrid system composed of the uncemented CLS expansion cup and the cemented MS-30 femoral component. Included in this study were 109 women and 36 men with the mean age of 64.2 years (range 25 to 87) at the time of the surgery. The mean follow-up time was 7.5 years (range 6 to 12). The Harris Hip Score and radiographic analyses were used for the most recent assessment. Five patients died during the follow-up period. Two hips were dislocated and managed by open reduction. The mean Harris Hip Score before surgery was 38.4 (range 15 to 57) and 91.3 (range 64 to 100) at the last follow-up. Although a radiolucent line has been detected around the femoral component in four hips, no revision has been considered yet. No radiological evidence of loosening and detectable migration have been observed in any of the acetabular components. The hybrid replacement, consisting of the uncemented acetabular CLS expansion cup and the cemented MS-30 femoral stem, yielded overall good results after medium-term duration of follow-up.