Vivacit-E Post-market Follow-up Study

The objectives of this study are to obtain clinical performance (outcomes) data and survivorship for commercially available Vivacit-E (HXPE) liners. This will be done by analysis of polyethylene wear, validated outcome measurement tools, radiographs, and reported adverse events data.

Inclusion Criteria: * Patient is 18 to 60 years of age, inclusive. * Patient is skeletally mature. * Patient qualifies for primary unilateral or bilateral total hip arthroplasty (THA) based on physical exam and medical history including at least one of the following: * Osteoarthritis * Avascular necrosis (AVN) * Post-traumatic arthritis * Congenital hip dysplasia * Patient has no history of previous total hip replacement or arthrodesis of the affected hip joint(s). * Patient is willing and able to provide written informed consent. * Patient is willing and able to cooperate in the required post-operative therapy. * Patient is willing and able to complete scheduled follow-up evaluations as described in the Informed Consent. * Patient has participated in the Informed Consent process and has signed the IRB/EC approved informed consent. Exclusion Criteria: * Patient is unwilling or unable to give consent or to comply with the follow-up program. * Patient has a total prosthetic hip replacement device (including surface replacement arthroplasty, endoprosthesis, etc. in the affected hip joint(s). * Inflammatory Arthritis * Rheumatoid Arthritis * The patient is: * a prisoner mentally incompetent or unable to understand what participation in the study entails a known alcohol or drug abuser * anticipated to be non-compliant * The patient has an acute, chronic, or systemic infection(s). * The patient has total or partial absence of the muscular or ligamentous apparatus. * The patient has neuromuscular compromise, vascular deficiency or other conditions in the affected limb that may lead to inadequate skeletal fixation. * The patient has osteoradionecrosis. * The patient has lack of bony structures proximal or distal to the operative joint, so that good implant fixation is unlikely or impossible. * The patient has local bone tumors/cysts in the bone to be retained that the implanting surgeon determines could inhibit implant fixation. * The patient is skeletally immature. * The patient has any concomitant disease that can jeopardize the functioning and the success of the implant. * The patient is known to be pregnant. * The patient has a known sensitivity or allergic reaction to one or more of the implanted materials which include metal (titanium, tivanium, tantalum, cobalt, chromium, nickel) and ceramic.