Effects of harvest and selected cartilage repair procedures on the physical and biochemical properties of articular cartilage in the canine knee

This study utilizes a canine model to quantify changes in articular cartila ge 15-18 weeks after a knee joint is subjected to surgical treatment of iso lated chondral defects. Clinical and experimental treatment of articular ca rtilage defects may include implantation of matrix materials or cells, or b oth. Three cartilage repair methods were evaluated: microfracture, microfra cture and implantation of a type-II collagen matrix, and implantation of an autologous chondrocyte-seeded collagen matrix. The properties of articular cartilage in other knee joints subjected to harvest of articular cartilage from the trochlear ridge (to obtain cells for the cell-seeded procedure) w ere also evaluated. Physical properties (thickness, equilibrium compressive modulus, dynamic compressive stiffness, and streaming potential) and bioch emical composition (hydration, glycosaminoglycan content, and DNA content) of the cartilage from sites distant to the surgical treatment were compared with values measured for site-matched controls in untreated knee joints. N o significant differences were seen in joints subjected to any of the three cartilage repair procedures. However, a number of changes were induced by the harvest operation. The largest changes (displaying up to 3-fold increas es) were seen in dynamic stiffness and streaming potential of patellar groo ve cartilage from joints subjected to the harvest procedure. Whether the ch anges reported will lead to osteoarthritic degeneration is unknown, but thi s study provides evidence that the harvest procedure associated with autolo gous cell transplantation for treatment of chondral defects may result in c hanges in the articular cartilage in the joint.