Prevention of chondrocyte apoptosis following acute osteochondral injury

Objective To explore the characteristics of chondrocyte apoptosis following acute osteochondral injury and the effect of intra-articular sodium hyaluronate injection in prevention of chondrocyte apoptosig. Methods Acute osteochondral injuries were created by drilling holes in knees at both sides of 28 rabbits according to Costouros' method. The experimental and control sides were randomized in each animal. Another four rabbits served as a normal control which received dissection of knee joint capsule without osteochondral injury. The experimental knee was injected with 1 % sodium hyaluronate at the end of the operation and then every week postoperatively. TUNEL and fluorescence-activated cell sorter (FACS) were applied to study the injured femoral condyles obtained at different intervals following the drilling injury. Results From day 4 after injury, the injured cartilage specimens displayed a statistically significant increase in overall level of apoptosis. Chondrocyte apoptosis was significantly reduced in the experiment knees compared with the injured ones. Conclusions Chondrocyte apoptosis may contribute to the subsequent development of post-traumatic arthritis. Intra-articular sodium hyaluronate injection just after acute osteochondral injury can suppress chondrocyte apoptosis, and thus help prevent the knee from post-traumatic arthritis.