The Results of Cementless Total Hip Arthroplasty for Primary Osteoarthritis Compared with Avascular Necrosis of the Femoral Head

Purpose: Cementless total hip arthroplasty was performed to treat primary osteoarthritis of the hip and avascular necrosis of the femoral head. The clinical and radiological results of the acetabular cups and femoral stems were compared. Materials and Methods: The subjects were 84 cases who underwent primary cementless total hip arthroplasty from March 1992 to May 2001. The 84 cases were followed up for at least eight years. The patients were divided into the following two groups: group (A), 38 cases of degenerative osteoarthritis of the hip; and group (B), 46 cases of avascular necrosis of the hip. The clinical evaluation was conducted based on the Harris Hip Score (HHS). A radiological assessment was performed to determine if osteolysis or acetabular loosening had occurred. The results were analyzed statistically. Results: The postoperative HHS of groups A and B at the final follow-up were 92.1 and 91.2, respectively (p=0.483). The radiological results revealed 9 and 15 cases of acetabular osteolysis (p=0.671) and 1 and 3 cases of vertical migration of the acetabular cups in the group A and B, respectively. Eight and 7 complications (p=0.572) were encountered in group A and B, respectively. Among these, 4 and 5 cases of revisional total hip arthroplasty were performed in group A and B, respectively. The results of survival analysis were similar in the two groups (p=0.969). Conclusion: The clinical and radiological features of the acetabular cups and stems were similar in the two groups. Nevertheless, further studies will be needed due to the high rate of polyethylene liner wear and osteolysis around the acetabular cups or femoral stems.