Inclusion Criteria:

• Patients who have ARCO Stage I and Stage II (i.e., no evidence of collapse on MRI or x-ray) atraumatic osteonecrosis of the femoral head (ONFH), all lesion sizes, major risk factors (e.g., corticosteroids, alcohol, organ recipient). Idiopathic patients for which no risk factor has yet been identified will be included. The patients will include all sexes, ethnicities, and races. The age range to be recruited is 18 to 90 years.
• The orthopaedic surgeon has decided that core decompression (with or without BMAC) is the appropriate treatment.
• The procedure has been discussed and agreed to by the patient.

Exclusion Criteria: 

• ONFH patients associated with sickle cell disease, major trauma, post-irradiation ONFH, Gaucher Disease, and Perthes Disease will be excluded as the natural history of the disease in these patients may potentially differ from that of secondary ONFH (e.g., corticosteroid, alcohol).
• Patients who are pregnant or breastfeeding will be excluded from this study, as it is not advisable for radiographs to be taken.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Eligibility last updated 1/16/24. Questions regarding updates should be directed to the study team contact.