Anterior cruciate ligament reconstruction using chitin-coated fabrics in a rabbit model

Experimental anterior cruciate ligament (ACL) reconstruction was carried out in a rabbit model, in which a chitin-coated polyester graft was used as the scaffold, and a noncoated graft was used as a control graft. After 8 weeks implantation, a mechanical test of the knee and histometric measurement of the graft and surrounding tissues were carried out. A tensile test of the femur-graft-tibia specimen showed that the knee treated with the coated graft had a peak resistance force of 42.2 +/- 12.7 N, which was significantly greater than the 19.2 +/- 15.3 N of the knee treated with the control graft. The histometric measurement revealed that the area of bone tissue within the section of the coated graft in the femoral bone tunnel was 3.43 +/- 1.73 mm(2), which was significantly greater than the area of 0.29 +/- 0.37 mm(2) of the control graft. Similarly, the area of soft tissue within and around the midsubstance of the coated graft located in the articular cavity was significantly greater than that of the control graft. The chitin coating enhanced the formation of bone tissue in the femoral bone tunnel and soft tissue in the articular cavity, and increased the attachment strength of the graft to the bone. Thus, the efficacy of the chitin coating for the ACL reconstruction scaffolds was demonstrated.