Brief Summary: Post-market clinical outcomes study to collect data on the short- and long-term outcomes for subjects who are undergoing or have undergone the Subchondroplasty® (SCP®) Procedure in the hip in a standard clinical setting. Outcomes to be assessed include medication usage, pain, function, activity levels and patient satisfaction.

Detailed Description: This study is designed as a post-market, single arm, non-randomized multi-center investigation. Male and female subjects, at least 18 years of age, with at least one subchondral bone defect in the form of a cyst and/or bone marrow lesion (BML), insufficiency fracture or bone defect associated with early stage avascular osteonecrosis (AVN) in the femoral head, femoral neck and/or acetabulum who are suitable candidates for use of AccuFill during the Subchondroplasty Procedure are eligible for enrollment in this study. A maximum of 15 study sites, in the United States of America, will enroll a target of 50 subjects. Each Investigator must obtain IRB approval, or favorable opinion by an EC, prior to consent of the first subject; no study-related procedures can occur without the approval and oversight of a registered IRB or EC. If the study site does not have an IRB of record, a central IRB may be utilized upon approval by Zimmer Biomet. Demographics, medical history, hip history and use of pain medication and therapy will be recorded at the time of subject consent. Additionally, patient reported outcomes measures will be obtained pre-operatively. Operative details including the SCP Procedure, concomitant surgical procedures and intraoperative safety events will be recorded at the time of surgery. Prospective subjects will be considered enrolled in this study once their Subchondroplasty Procedure has been performed. Subjects will complete only the Numeric Pain Scale at 2 weeks post-operatively. Thereafter, subjects will complete self-reported outcomes measures post-operatively at 6 weeks, 12 weeks, 6 months, 1 year and 2 years. These measures include information on pain medication and therapy, pain levels, function, activity and subject satisfaction. Screening for adverse events and conversion will occur throughout the study. Subjects will complete the study at 2 years or will be withdrawn if they undergo conversion of the Subchondroplasty site. For the purposes of this protocol, a conversion will be defined as total hip arthroplasty or any procedure involving removal of the AccuFill material on the index hip.