To evaluate the mid and long-term clinical and radiological results of cementless total hip arthroplasty using a stem of anatomic design, and to determine those factors that influence stem loosening.

We analyzed 102 hips (83 patients) managed with cementless total hip arthroplasty using the stem of anatomic design with an average of 6.2 years of follow-up Twelve hips showed radiological loosening of the femoral stem. We compared these 12 hips with 24 well-fixed hips.

The Harris hip score was 90.1 an average (range: 70-100) and the incidence of thigh pain was 19.1% (21 hips) at the last followup. The rate of revision was 2.9% (three hips) for the femoral side. Twelve hips (11.7%) showed radiological loosening on the femoral side, namely, subsidence of the stem (five hips), change in the position of the stem (six hips), and extensive osteolysis (one hip). The two groups differed significantly in femur of the wear rate of polyethylene liner, osteolysis, and stem fill.

Operation involving an anatomic prosthesis should be properly performed to fill the proximal part of femur, and the wear the bearing surface should be improved. Furthermore, the prevention of thigh pain should be considered in the design of anatomic femoral stem.