Surface‐Based Cartilage Restoration for Focal Chondral Defects in the Knee

Abstract Focal chondral defects of the knee pose a persistent clinical challenge due to the limited regenerative potential of articular cartilage. Although objective assessment of cartilage restoration remains difficult, the primary clinical goal is to reduce pain and improve joint function. Successful outcomes depend foremost on appropriate patient selection, with treatment guided by lesion location, size, depth, and individual patient factors. Surgical restoration follows 2 principal pathways based on (1) the presence or absence of subchondral bone loss or insufficiency and (2) the presence of severe bone marrow edema with cystic changes and prior marrow stimulation (drilling or microfracture). Lesions with significant bone loss (>6‐8 mm) require combined reconstruction of the osseous bed and cartilage surface, using either an osteochondral autograft or allograft or layered bone grafting followed by cartilage restoration (sandwich technique). In the absence of bone loss with intact subchondral bone plate, surface‐based repair options include cell‐based autologous chondrocyte implantation, particulated juvenile allograft cartilage, particulated autologous cartilage, and minced chondral allograft with extracellular matrix scaffolding. Each technique offers distinct advantages related to biological potential, surgical staging, cost, durability, and outcomes with corresponding limitations in graft availability, rehabilitation demands, and long‐term outcomes. This infographic presents a practical, bone‐based decision algorithm for surface‐based chondral repair and summarizes indications, technical considerations, and current outcomes evidence to guide optimal treatment selection and clinical decision‐making.