Explanation:
Excessive acetabular cup inclination increases edge loading and polyethylene wear. When inclination exceeds approximately 50–55 degrees, the contact area decreases and stresses increase. This leads to accelerated wear debris production and osteolysis. Optimal cup inclination is generally considered around 40–45 degrees. Proper surgical technique and intraoperative guidance help achieve correct positioning. Malposition remains a leading cause of premature prosthetic failure. Reference: Lewinnek GE. "Dislocations After Total Hip Replacement Arthroplasties." Journal of Bone and Joint Surgery, 1978.