Advances in processing and preparation techniques of subchondral bone for the successful integration of osteochondral allografts

Introduction: Osteochondral allograft transplantation (OCA) is a well-established treatment for focal cartilage defects, yet failure to achieve graft-host bone integration remains a significant contributor to suboptimal outcomes. Objectives: This narrative review aims to critically evaluate current and emerging techniques for the processing and preparation of subchondral bone in fresh OCAs, with a focus on improving graft incorporation and long-term clinical success. Methods: A narrative review of preclinical and clinical literature was conducted using PubMed with inclusion criteria and search terms limited to studies addressing preservation methods (“lavage,” “CO₂,” and “centrifugation”), marrow removal techniques, and biologic augmentation (“concentrated bone marrow aspirate (cBMA)”) specific to the subchondral bone. Relevant experimental and retrieval studies were included to assess translational relevance. Results: Preservation techniques such as pulse lavage, pressurized CO₂, and high-speed centrifugation show promise in reducing immunogenic marrow elements. Biologic augmentation with concentrated bone marrow aspirate may enhance osteoinduction, although clinical evidence remains mixed. Intraoperative factors, including graft depth and subchondral alignment, are critical for successful integration. Current literature lacks standardization of preparation protocols and long-term studies directly linking these interventions to improved patient outcomes. Conclusions: While chondrocyte viability remains important, subchondral bone integration is increasingly recognized as a critical determinant of OCA success. A shift toward bone-focused optimization—including preparation, immunologic considerations, and biologic enhancements—may improve consistency and clinical durability in OCA transplantation.