Evaluate the Safety and Effectiveness of the Polymotion Hip Resurfacing (PHR) System Compared to Total Hip Arthroplasty

In order to be eligible to participate in this study, subjects must meet all of the following criteria:

1. Requires primary hip resurfacing arthroplasty due to:

2. non-inflammatory arthritis (degenerative joint disease) such as osteoarthritis, traumatic arthritis, or

3. mild dysplasia/developmental dislocation of the hip (DDH) up to Crowe Grade 1.

4. Harris Hip Score < 70 points.

5. Skeletally mature, age ≥21 and <65 years.

6. Physically and mentally able and willing to comply with the Protocol, including the ability to read and complete required forms and willing and able to adhere to the scheduled follow-up visits and requirements of the Protocol.

Subjects who meet any of the following criteria will be excluded from participating in this study:

1. Inadequate bone stock or bone quality to support the device based on a Canal-Bone Ratio (CBR-7) of >0.45.0F

2. Severe osteopenia, a medical history or increased risk of severe osteoporosis or severe osteopenia, a history of fragility fracture, and other conditions that lead to increased bone resorption

3. Osteonecrosis or avascular necrosis (AVN)

4. Multiple cysts of the femoral head (> 1cm) or cysts crossing the head-neck junction

5. Metabolic disorders which may impair bone formation (e.g., osteomalacia, osteogenesis imperfecta, parathyroid disease, rickets, etc.)

6. Severe femoral head deformities that will prevent fixation of the prosthetic resurfacing femoral head

7. Inflammatory arthritis such as rheumatoid arthritis (RA)

8. Severe proximal femoral rotational deformity in whom appropriate combined anteversion of femoral-acetabular construct is unachievable

9. Severe acetabular dysplasia/development dislocation of the hip, defined as Crowe Grade ≥ 2

10. Previous surgical intervention on index hip (e.g., treatment of hip fracture, arthroscopy)

11. Severe medical comorbidities, including:

12. severe cardiopulmonary disease,

13. congestive heart failure,

14. severe liver or kidney dysfunction,

15. end-stage renal disease,

16. severe uncontrolled diabetes,

17. history of IV drug use,

18. history of hypercoagulable state or pulmonary embolism,

19. severe lumbar spinal stenosis,

20. vascular insufficiency, muscular atrophy, or neuromuscular disease severe enough to compromise implant stability or post-operative recovery,

21. neuropathic arthropathy (Charcot joint),

22. immunosuppression or other immunodeficiency disorders, e.g., diseases such as Acquired Immune Deficiency Syndrome (AIDS) or post-organ transplant and on high doses of corticosteroids.

23. Incompetent or deficient soft tissue surrounding the joint (e.g., hip abductor muscle deficiency)

24. BMI > 40

25. Active or suspected infection in or around the hip joint

26. Known or suspected metal sensitivity (e.g., jewelry) or allergy to any implant materials

27. Pregnant or plan to become pregnant during the study duration

28. Current smoker