[Challenges in Primary Total Hip Arthroplasty].

Total hip arthroplasty (THA) represents a meticulously standardized procedure with highly satisfactory results for surgeons and patients alike. Anyhow, due to rare diseases, anatomic varieties or in posttraumatic situations, the restauration of a normal hip joint anatomy and physiological kinematics can become a big challenge for the treating surgeon. This article gives an overview of the variety of these challenging conditions (including developmental hip dysplasia, osteopetrosis, skeletal dysplasia, Paget's disease and extraarticular deformities) and with a selection of complex cases it should give the reader some thought-provoking impulses considering the management of complex primary THA cases. This includes with the choice of implant, intraoperative characteristics, certain pitfalls and postoperative considerations alike. As a result, it should minimize the risk for complications in these complex cases without minimizing the patient's expectations in a nearly normal hip function and painless movement.