Effect of HBOT on Femoral Head Avascular Necrosis (AVN)

Inclusion Criteria: * Provision of signed and dated informed consent form * Stated willingness to comply with all study procedures and availability for the duration of the study * Diagnosed with femoral head avascular necrosis * Enrolled into Yale Avascular Necrosis Program * Avascular necrosis lesion is classified as ARCO I or ARCO II by Investigator * Surgical Candidate for Core Decompression using 3D image guidance with bone marrow aspirate concentrate Exclusion Criteria: * Hip has already collapsed due to severe avascular necrosis (ARCO III or ARCO IV) * Medical comorbidities that prevent them from being a surgical candidate (example: obesity) * Absolute contraindications to HBOT, including severe decompensated cardiac failure or lung disease putting them at high risk for pneumothorax * Pregnant * Prisoner * Does not sign Informed Consent Form