OBJECTIVETo explore the effect of the expanded capsule on biomechanics of the transplanted autologous costal cartilage.

METHODSTen New Zealand white rabbits aged 3 months were involved and four 15 ml tissue expanders were implanted symmetrically on the back of each rabbit. After 1 month, expanded capsules were removed (experimental group) on the left side and were reserved (control group) on the right side. Meanwhile, the 6th and 7th costal cartilage without the perichondrium were taken out and each cartilage was divided into two pieces and put under the expanded capsule symmetrically. The cartilage at the upper sides and lower sides were taken out at 4 weeks and 8 weeks later, respectively. All the cartilages were sculptured for the demand of the machine text. The tension and compression property of the cartilages were assessed by the material testing machine (Instron 5967) and the results were analyzed statistically.

RESULTS8 weeks lateral, the average ultimate tension strength was (4. 954 + 2. 8) MPa in experimental group and (2.939 + 0.842) MPa in control group. The average compressive strength was (58.74 ± 13.77) MPa in experimental group, and (47.61 ± 11.41) MPa in control group. The biomechanics property of the cartilages in the experimental group is better than the control group, and the differences were statistically significant.

CONCLUSIONSRemoving the expanded capsule is benefical to maintain the biomechanics of autologous costal cartilage.