Continuum™ Metal Bearing System in Total Hip Arthroplasty

Inclusion Criteria: * Patient is 18 to 75 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 the following: * Avascular necrosis (AVN) Osteoarthritis (OA) * Inflammatory arthritis (i.e. Rheumatoid arthritis) * Post-traumatic arthritis * Patient has no history of previous prosthetic replacement device (any type, including surface replacement arthroplasty, endoprosthesis, etc.) of the affected hip joint(s). * Patient has a Harris Hip Score \<70 in the affected hip * 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 Ethics Committee approved informed consent. Exclusion Criteria: * 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 a neuromuscular disorder, vascular disorder or other conditions that could contribute to prosthesis instability, prosthesis fixation failure, or complications in postoperative care. * The patient has a neurologic condition in the ipsilateral or contralateral limb which affects lower limb function. * The patient has a diagnosed systemic disease that could affect his/her safety or the study outcome. * The patient is known to be pregnant. * The patient is unwilling or unable to give consent, or to comply with the follow-up program. * The patient has received an investigational drug or device within the previous 6 months. * The patient has an active or latent infection in or about the affected hip joint or an infection distant from the hip joint that may spread to the hip hematogenously. The patient has insufficient bone stock to fix the component. Insufficient bone stock exists in the presence of metabolic bone disease (i.e. osteoporosis), cancer, and radiation. Note: Dual Energy X-ray Absorptiometry (DEXA) may be used to assess the presence of adequate bone stock. * The patient has known local bone tumors and/or cysts in the operative hip. * The patient has a known allergic reaction to one or more of the implanted material. * The patient is Grade III obese with a Body Mass Index (BMI) ≥ 40. * The patient has osteoradionecrosis in the affected hip joint * Kidney insufficiency (Kidney insufficiency will be determined based on eGFR value. See Blood Analysis Report CRF for details)