Technical Enhancements and Update on Chondrocyte Implantation

Various cartilage injury treatments such as bone marrow–stimulating techniques and autologous osteochondral grafting have been described. Good clinical results have been attained with these methods for small cartilage injuries. However, these methods are controversial for larger lesions. In 1994, Brittberg et al first reported on the clinical results after autologous chondrocyte implantation using a monolayer culture to repair cartilage injury. Although their surgical procedure heralded a breakthrough in the field of cartilage repair, various potential problems have been identified such as chondrocyte leakage from the defect site, chondrocyte dedifferentiation, and potential uneven distribution of grafted chondrocytes. Despite good clinical results, re-creation of a 3-dimensional zonal architecture of chondrocytes in repair tissue has remained elusive. Lastly, a multicenter report by Zaslav et al delineated high rates of secondary surgical procedures relating to periosteal detachment, periosteal overgrowth, and adhesions. Newer technical improvements in cell selection, surgical technique as well as scaffold development have recently been reported. This article describes these technical enhancements including the use of collagen patch, second-generation cell growth on scaffolds, cultured chondrocytes embedded in Atelocollagen gel, and a fourth-generation arthroscopic gel chondrocyte implantation in a 3-dimensional fibrin gel. Further longitudinal study will hopefully show improved long-term structural results from these enhancements over time.