Purpose of review: Regeneration of damaged articular cartilage remains one of the most challenging problems in orthopedic surgery. Distinct surgical procedures were developed for the repair of focal cartilage defects and this review will focus on recent aspects of cell-based healing approaches that aim to achieve restoration of normal joint function by regenerating hyaline cartilage.
Recent findings: Surgical techniques are rapidly developing, and include resorbable biomaterials and expanded human mesenchymal stem cells to avoid disadvantages conferred by periosteal flaps and autologous chondrocytes. While expansion of mesenchymal stem cells seems to be safe and applicable, some concern exists about the stability of mesenchymal stem cells set to path to become chondrocytes, since common in-vitro protocols of chondrogenesis induce a program related to endochondral ossification which may finally yield only transient cartilage. SUMMERY: Bone marrow-stimulating techniques and autologous chondrocyte transplantation confer pain relief to the patients, and are superior to no treatment. Similar in their clinical outcome, they induce fibrocartilaginous repair tissue which may mature towards hyaline cartilage over time. Gained knowledge in the regulation of chondrogenesis, the role of host cell recruitment, transplanted cells, defect-filling materials and the influence of factors from subchondral bone will help to improve surgical procedures to allow their application to larger defects and patients with advanced signs of osteoarthritis.