Expert Consensus on Robot-Assisted Vascularized Bone Grafting for the Treatment of Early-Stage Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) remains a progressive clinical challenge that predominantly affects young and active adults between 20 and 50 years of age. Without timely and effective surgical intervention, natural disease progression leads to structural subchondral fracture, articular surface collapse, and secondary hip osteoarthritis, ultimately necessitating total hip arthroplasty (THA). Given the elevated lifetime revision rates of prosthetic replacements in young patients, joint-preserving strategies are prioritized during the precollapse window [primarily Association Research Circulation Osseous (ARCO) stages I, II, and early IIIA]. Vascularized bone grafting, specifically free vascularized fibular grafting (FVFG) and pedicled vascularized bone transfers, provides both living osteogenic scaffolding and direct arterial perfusion. Traditional manual techniques are limited by steep learning curves, prolonged fluoroscopy exposure, multiple off-target guide-wire passes, and variable spatial placement of the graft. Computer-assisted orthopedic surgical robots, real-time optoelectronic navigation, and multimodal 2D/3D registration can improve spatial accuracy, reduce the number of drilling attempts, and support more reproducible subchondral seating. This multidisciplinary expert consensus synthesizes available clinical series, meta-analyses, biomechanical evaluations, and multicenter experience to provide standardized recommendations on indications, preoperative planning, surgical technique, perioperative management, expected outcomes, and future directions for robot-assisted vascularized bone grafting in early ONFH. The document emphasizes workflows that may reduce fluoroscopy exposure, operative time, and technical variability while optimizing graft placement near the subchondral plate in the weight-bearing region. Consensus statements are graded according to the strength of supporting evidence (primarily retrospective cohorts and low- to moderate-quality meta-analyses) and expert agreement.