Repair of articular cartilage defect in rabbit with type Ⅱ collagen sponge filling material / 中国组织工程研究

ABSTRACT

BACKGROUND: The repair of articular cartilage defect is always a problem that is dedicatedly solved by doctors of orthopaedics. Autologous perichondrium, periosteum or allografting of cartilage have been used previously; however, the source of the donor is limited, the fixation is difficult as well as the occurrence of endochondrial ossification and delamination between the inferior cartilage and reparative cartilage, etc. Type Ⅱ collagen, the main component of cartilage matrix, has certain effects in the repair of articular cartilage defect.OBJECTIVE: To investigate the effects of type Ⅱ collagen sponge filling on the repair of articular cartilage defect.DESIGN: A randomized controlled trial.SETTING and MATERIALS The study was conducted in the Guangzhou Institute of Traumatic Surgery. Materials were 24 adult male purebred New Zealand Rabbits(48 knees), ordinary grade, with a body mass of (2.29 ±0. 25) kg. Animals were fed with standard feeding in separate cage.INTERVENTIONS: A full-thickness defect in articular cartilage was made on the femoral trochlear surface by a drill of 5 mm in diameter and 3 mm in depth. Rabbits were allocated into filling group(type Ⅱ collagen sponge was grafted into left keen joint defect) and control group(right knee joint defect site was set as control) according to random number table.MAIN OUTCOME MEASURES: Gross morphological and histological observation of the defect repair in each dual week within 12 weeks after operation.RESULTS: During 10 - 12 weeks, in cuntrol group The defect area was repaired by white and soft tissue that had no resistance to press. The repaired tissue was still lower than the surrounding articular surface with clear boundary. By histological observation, it was found that the defect was repaired by the mechanism similar to inflammatory reaction and the defect is ultimately filled by the hyperplasia of hyaline degenerative fibrous tissues. In filling group the defect was repaired by semi-transparent, smooth, textured tissues with polish that had resistance to press as well as elasticity. The repaired tissue was almost similar to the shape of the surrounding cartilage,difficult to be distinguished. After histological observation, it was found that there was no inflammatory reaction, but active hyperplasia of inner bonetissue and cartilage tissues; a lot of osteoid tissues and trabeculation were found. Newlborn cartilage was fused with surrounding cartilage tissue and connected with surrounding tissues. Type Ⅱ collagen had significantly promoting effects in the repair of articular cartilage defect, and the repaired cartilage was close to normal cartilage. CONCLUSION: The self-made high purity type Ⅱ collagen sponge has favorable promoting effects in the repair of articular cartilage defect with good histocompatibility but without obvious toxic side effect.