Contemporary Management of Knee Chondral Defects, Part III: Cell-Based Cartilage Repair Including Autologous...

Cell-based cartilage repair strategies seek biologic regeneration of articular cartilage rather than mechanical resurfacing. These approaches are most appropriate for medium-to-large, contained focal defects in patients who have preserved alignment and subchondral bone who are willing to undergo staged procedures and prolonged rehabilitation. Autologous chondrocyte implantation, particularly in its matrix-induced form, represents the most established cell-based platform. Long-term follow-up studies demonstrate sustained improvements in patient-reported outcomes with acceptable reoperation and arthroplasty conversion rates beyond 10 years. Evidence remains the strongest for the technique as a class rather than for individual proprietary systems. In contrast, point-of-care orthobiologics, including bone marrow aspirate concentrate and platelet-rich plasma, are widely utilized despite heterogeneous protocols and limited high-level comparative data. Although short-term symptomatic improvements are frequently reported, structural imaging outcomes and durability remain inconsistent. Standardization challenges complicate interpretation of the existing literature. Emerging therapies, including adipose-derived regenerative cell systems, cord blood-derived mesenchymal stem cell constructs, and tissue-engineered osteochondral platforms, aim to enhance biologic regeneration while reducing procedural burden. Most remain investigational, with early-phase clinical trials and limited long-term outcome data. Cell-based repair occupies a distinct position within the joint-preserving continuum. Durable success depends on careful alignment between lesion characteristics and biologic plausibility. Failures often reflect application beyond appropriate constraints rather than technical inadequacy. Continued comparative studies are necessary to define durability, cost-effectiveness, and long-term joint preservation relative to structural and hybrid strategies.