Prospective Clinical Follow-up of the Echo Bi-Metric Microplasty Stem for Total Hip Arthroplasty

Inclusion Criteria: * Subjects are eligible for this trial if they satisfy all of the following criteria: * Patient is 18 to 65 years of age, inclusive * Patient is skeletally mature * Patient qualifies for primary unilateral or bilateral total hip arthroplasty based on physical exam and medical history including at least one of the following: * Osteoarthritis * 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 by other techniques * Patient has no history of previous total hip arthroplasty or arthrodesis of the affected hip joint(s) * Patient is willing and able to complete scheduled follow-up evaluations as described in the Informed Consent * Patient, or the patient's legally authorized representative, has participated in the Informed Consent process and is willing and able to sign an IRB- approved informed consent Exclusion Criteria: * Subjects will be excluded from this trial if they satisfy any of the following criteria as determined by the research staff or in the judgment of the treating physician: * Patient has a total prosthetic hip replacement device (including surface replacement arthroplasty, endoprosthesis, etc.) in the affected hip joint(s) * Patient is septic or has an active infection * Patient is uncooperative patient or is incapable of following directions * Patient is diagnosed with osteoporosis * Patient is diagnosed with a metabolic disorder which may impair bone formation * Patient is diagnosed with osteomalacia * Patient has distant foci of infections which may spread to the implant site