The Medacta International SMS Post-Marketing Surveillance Study

Inclusion Criteria: * Individuals with a severely painful and/or disabling hip joint with osteoarthritis, traumatic arthritis or developmental dysplasia of the hip or avascular necrosis of the femoral head. * In order to take part in this study, all study participants must be between the ages of 18 and 75 years of age, at the time of surgery. * Scheduled for a primary total hip replacement. Exclusion Criteria: * Active infection * Pregnancy * Mental illness where the known condition is likely to compromise the patient's ability to consent, affect the patient's assessment of their progress or complete the 10 year cycle of follow-up appointments and reviews * Grossly distorted anatomy (surgeon's discretion) * Osteomalacia where uncemented implant fixation is contraindicated * Active rheumatoid arthritis. * Osteoporosis * Metabolic disorders which may impair bone formation where uncemented implant fixation is contraindicated * Muscular atrophy or neuromuscular disease * Allergy to implant material * Any patient who cannot or will not provide informed consent for participation in the study * Those whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems