Cartilage graft resorption: An animal model

Abstract

Background: Autologous cartilage grafts have become an integral part of aesthetic and reconstructive plastic surgery. However, little objective information is available about the actual quantitative resorption of cartilage. Objective: This study sought to objectively quantify and compare the resorption of auricular and costal cartilage in an animal model over a 1-year time period. Methods: Autologous auricular and costal cartilage was harvested from New Zealand white rabbits. Each of the auricular and costal cartilage specimens was divided into 6 pieces. Two of the 6 pieces from each donor site were crushed, 2 were carved, and 2 were left untouched. One set of crushed, carved, and untouched cartilage from each site (auricular and costal) was placed into the subcutaneous tissues of the nasal dorsum, and a second set from each site was placed in the occiput as a control. In all, 12 pieces were placed into each of 7 rabbits, for a total of 84 grafts. Before placement, the mass and volume of each graft were measured through use of an analytic balance. After 1 year, the pieces were harvested and the mass and volume were measured again. Results: The resorption of ear cartilage was determined to be 16.4% ± 4.8% (P < .0001). For the costal cartilage group, an overall slight weight gain of 2.79% ± 8.61 % (P = .1032) was observed; this was not statistically significant. No statistically significant difference in resorption of cartilage occurred between the untouched (native), carved, and crushed cartilage. The reduction in cartilage volume approximately mirrored the observed weight reductions. No difference in volume reduction was observed between the nasal snout groups and the occipital controls. Conclusions: This preliminary animal study found that ear cartilage resorbs more than costal cartilage and that carving does not affect the amount of resorption.