The Effect of Perichondrium on Biological and Biomechanical Properties of Molded Diced Cartilage Grafts

Background Diced cartilage is a significant alternative approach to cartilage grafting. However, the viability and biomechanical properties of diced cartilage grafts remain to be improved, and the role of perichondrium is largely neglected. This study aimed to evaluate the histological and biomechanical effects of perichondrium on custom-shaped diced cartilage grafts constructed via a high-density porous polyethylene mold. Methods Seven New Zealand rabbits were used. Unilateral auricular cartilage was harvested and divided into 2 parts, with or without perichondrium, diced into 1 x 1 x 0.5 mm cubical pieces, and filled into high-density porous polyethylene molds. Three grafts with the perichondrium removed and 3 with the perichondrium preserved were implanted subcutaneously at the dorsum. The grafts underwent biomechanical and histological tests 4, 8, and 12 weeks after the implantation. Results The diced cartilage merged into integrated blocks without observable resorption in both groups at each time point. Additionally, the retention rate of weight was higher in the perichondrium-preserved group (P < 0.05). We observed regenerated cartilage that stained positively for type II collagen and glial fibrillary acidic protein (GFAP). A greater area of regenerated cartilage and higher scores of GFAP staining were observed in the perichondrium-preserved group (P < 0.05). The yield stress and modulus of elasticity were also higher in the perichondrium-preserved grafts from week 8 after implantation (P < 0.05). Conclusions Diced cartilage grafts with a custom shape can be constructed using a high-density porous polyethylene mold. The preservation of perichondrium can improve graft viability and biomechanical properties.