Innovations and future research directions on hip preservation management options for osteonecrosis of the femoral head

Table 1 Stage-stratified (association research circulation osseous-informed) treatment framework for osteonecrosis of the femoral head

Stage/risk group	Preferred treatment pathway	Key considerations
ARCO I–II (pre-collapse)	Core decompression (single large-bore vs multiple small-diameter) ± BMAC	Best-evidence window for preservation; outcomes vary with lesion size/location and non-standardized biologic processing/dose[1,3,5,8-10]
High-risk pre-collapse (large/lateral lesions; threatened subchondral integrity)	Add mechanical support: SHD + impaction grafting or selected implants (e.g., AVN cage)	Stage/lesion burden and rehabilitation strongly influence survivorship; avoid equating finite element analyses with clinical outcomes[13-16]
ARCO III (“borderline” early post-collapse)	Selected investigational preservation (e.g., PRFH) vs early transition planning	Evidence is early; cartilage–implant interface and acetabular wear remain unresolved risks[16,17]
Advanced ARCO III-IV/secondary arthritis	THA	Define a transition point; emphasize preoperative planning in complex anatomy[20]

BMAC: Bone marrow aspirate concentrate; AVN: Avascular necrosis; SHD: Surgical hip dislocation; THA: Total hip arthroplasty; PRFH: Replacement of the femoral head; ARCO: Association Research Circulation Osseous.