Knee Cartilage Repair An Update
Background: Chondral and osteochondral defects of the knee present significant clinical challenges due to the limited intrinsic regenerative capacity of articular cartilage. These lesions often result from acute trauma or repetitive microtrauma and, if left untreated, increase the risk of secondary osteoarthritis, particularly in young and athletic populations.
Objective: This article provides a comprehensive update on current surgical techniques for knee cartilage repair, evaluating their methodologies, clinical outcomes, and comparative efficacy to guide orthopedic decision-making.
Key Points: Surgical interventions are categorized into palliative, reparative, substitutive, and regenerative approaches. Bone marrow stimulation via microfracture remains a common first-line treatment for small defects, though its reliance on fibrocartilage formation may lead to long-term clinical deterioration. Augmentation techniques using scaffolds, such as autologous matrix-induced chondrogenesis (AMIC), aim to stabilize the initial clot. Osteochondral autograft transfer (OAT) and allograft transplantation (OCA) provide immediate hyaline cartilage replacement, with OCA being preferred for larger defects. Autologous chondrocyte implantation (ACI) and its subsequent matrix-induced generations (MACI) offer regenerative potential, showing superior durability for extensive lesions compared to microfracture. Emerging one-stage techniques, including minced cartilage and mesenchymal stem cell applications, are currently under evaluation. Comparative data suggest that while short-term outcomes are often similar across techniques, OAT and ACI may offer more sustainable results and higher rates of return to sport for specific patient cohorts.
Conclusion: No single technique currently restores native hyaline cartilage perfectly. Treatment selection must be individualized based on patient age, activity level, and lesion characteristics, utilizing a structured algorithmic approach to optimize clinical outcomes.
