Non-significant Effects of The Geometric Shape of Autologous Cartilage Grafts on Tissue Healing: An Animal Study.

BACKGROUND: The reconstruction of cartilage defects for cosmetic and/or functional reasons has become routine in plastic and reconstructive surgery. However, it remains challenging due to the slow turnover and low viability of cartilage grafts. Although autologous grafts can be used to determine the shape of the defect in cartilage-reconstruction surgeries, the effect of defect shape on cartilage healing has not been reported. Here, we present the first study aiming to investigate the influence of cartilage graft geometry on healing. METHODS: Twelve New Zealand white rabbits were used in the study. Square-, rectangle-, sphere-, and fusiform-shaped cartilage defects were applied to both ears with 1-cm2 geometric templates that completely elevated the cartilage tissue without damaging the opposite perichondrium. As a control, the removed cartilage was sutured back to the right ear, whereas the left ear was sutured back without any graft. Histological examinations were made on samples taken during surgery and those taken four months post-surgery. Chondrocyte production and organisation, chondrocyte vacuolisation, collagen synthesis, proteoglycan levels, vascularisation, focal bleeding, and peripheral proliferation were scored independently by two histologists. RESULTS: There was no statistically significant difference in the growth rates of either the control or experimental cartilage tissues when compared with that of the initial cartilage tissue (p = 0.083). Histologic comparisons revealed better outcomes in the grafted cartilage groups compared to those receiving the donor cartilage, but this was not statistically significant. CONCLUSIONS: This study demonstrates that the geometric shape of the defect has no significant effect on cartilage healing. LEVEL OF EVIDENCE: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .