MDR - PMCF Study for RingLoc Bipolar Acetabular Cup and Endo II Femoral Heads

Inclusion Criteria: * Patient must be 18 years of age or older and skeletally mature * Patient must have undergone hip hemiarthroplasty surgery with the RingLoc Bipolar Acetabular Cup or Endo II Femoral Head for a cleared indication, greater than or equal to eight years previous to the date of study consent. Cleared indications for the RingLoc Bipolar and Endo II Heads include the following: * Noninflammatory degenerative joint disease including osteoarthritis and avascular necrosis * Rheumatoid arthritis * Correction of functional deformity * Treatment of non-union, femoral neck fracture, and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques. Exclusion Criteria: * Any medical diagnosis present at the time of surgery that, at the Investigator's discretion, could compromise the implant's survivability * Off-label use or not according to the approved instructions for use (IFU) of study devices * Revision procedures where other treatment or devices have failed * Uncooperative patient or patient with neurologic disorders who is incapable of following directions * Patient has a psychiatric illness or