We report the medium term outcome of a 15 degrees face-changing acetabular cup in THA due to secondary OA in DDH. We analysed 28 Hips in 26 patients who underwent THA between May 2007and September 2009. There were 20 females and 6 males with a mean age of 52 yrs (range 33–68yrs). All patients received a cementless Exceed Advanced Bearing Technology 15° Face-changing cup (Biomet) with a ceramic liner through a posterior approach. A cementless or a cemented femoral stem, with 28 or 32mm Biolox Delta ceramic head, was used in all cases. All patients started full weight-bearing the next day. The average clinical and radiological follow-up was for 50 months (range 36–76 months). The mean Harris Hip Score improved to 94 and the Oxford Hip Score improved to 44. There was 100% survivorship of the hip joint for both components. Post-operative radiographs revealed integration of the cup with no signs of loosening or osteolysis. The mean covered acetabular lip inclination angle was 51 degrees (range 43–61)and the true inclination angle of the bearing was 36 degrees (range 28–46). The clinical results support the use of the cementless 15 degrees face-changing acetabular cup in the dysplastic acetabulum

We report the use of a 15° face-changing cementless acetabular component in patients undergoing total hip replacement for osteoarthritis secondary to developmental dysplasia of the hip. The rationale behind its design and the surgical technique used for its implantation are described. It is distinctly different from a standard cementless hemispherical component as it is designed to position the bearing surface at the optimal angle of inclination, that is, < 45°, while maximising the cover of the component by host bone.