Primary total hip replacements are routine procedures with good outcomes. To ensure uniformly good results it is important that a thorough preoperative assessment of the patient is made. The prosthesis best suited to the patient and the pathology must be carefully selected and the optimal surgical technique must take into account patient, pathology and prosthesis parameters. We discuss patients’ problems such as morbid obesity, the different arthritides and neuromotor abnormalities. Acetabular problems, including dysplastic acetabula and acetabula protrusio, are dealt with in detail. We examine post-traumatic hip pathologies, including retained fracture implants, nonunions and ankyloses. On the femoral side, dysplastic
