This study is in response to the Food and Drug Administration (FDA) call to all manufacturers with 510(k) clearance for metal-on-metal (MoM) total hip arthroplasty (THA) devices to conduct postmarket surveillance studies. MicroPort has various acetabular shells, acetabular liners, fixation screws, femoral heads, femoral stems, modular necks, and proximal bodies currently cleared for MoM indications. Together these components comprise the Wright Medical Technology (WMT) MoM THA System. The primary objective of the study is to determine the incidence of adverse local tissue reactions (ALTR) in each THA implanted with the WMT MoM THA System overall and to create cross-sectional epochs of ≤ 8 years and > 8 years, since implantation.

Inclusion Criteria:

To be included in Group 1, subjects must meet all of the following criteria:

1. Has been implanted with appropriate components of the WMT MOM THA System

2. Has previously undergone primary THA for any of the following:

   1. non-inflammatory degenerative joint disease including osteoarthritis, traumatic arthritis, or avascular necrosis;
   2. inflammatory degenerative joint disease including rheumatoid arthritis;
   3. correction of functional deformity.

3. Is willing and able to complete required study visit(s) and assessments

4. Plans to be available for the required study visit

5. Is capable of providing sufficient blood for sampling according to blood draw procedures

6. Is willing to sign the approved Informed Consent document

Previously implanted bilateral subjects can have both THAs enrolled in the study provided: 1) the specified combination of components were implanted in both, 2) all other aspects of the Inclusion/Exclusion Criteria are satisfied, 3) enrollment does not exceed the subject count specified in the Clinical Trial Agreement and protocol enrollment strategy, and 4) the subject agrees to a second Informed Consent document and data collection specific to the second THA. Enrollment and treatment of a previously unimplanted hip is not permitted in this study.

To be included in Group 2, subjects must meet all of the following criteria:

1. Does not have a metal implant (total hip, total knee, spinal, etc.) with the exception of dental implants
2. Is not an employee of the Investigator
3. Is willing and able to provide Informed Consent document
4. Is willing and able to attend the requested study visit(s) and assessments
5. Is capable of providing sufficient blood for sampling according to blood draw procedures

Exclusion Criteria:

Subjects will be excluded from either study group if they meet any of the following criteria:

1. Subject is currently enrolled in another clinical investigation which could affect the endpoints of this protocol
2. Subject is unwilling or unable to sign the Informed Consent document
3. Subject has documented substance abuse issues
4. Subject has an emotional or neurological condition that would pre-empt their ability or willingness to participate in the study
5. Subject is currently incarcerated or has impending incarceration
6. Group 1 only: Subject has a condition or previously implanted medical device that contraindicates MRI (e.g. pacemaker, implantable defibrillator)
7. Group 1 only: Subject was skeletally immature (less than 21 years of age) at time of implantation

Group 1: Subjects previously implanted with components of the Wright Medical Technology (WMT) Metal-on-Metal (MoM) Total Hip Arthroplasty (THA) System

Group 2: Control, non-implanted subjects