OBJECTIVETo investigate the influence on costal cartilage reparative regeneration by replanting the small blocks of autogeneic cartilage into the perichondrial pocket at the donor-site.

METHODS16 rabbits (8-10 weeks old, 1.8-2.2 kg) were randomly divided into four groups as three experimental groups and one control group. The 1.5 cm in length of costal cartilage defect was made in experimental groups with the perichondrium and costochondral junction left completely intact. The cartilage defect was closed by 3 methods as saturation directly, or replanting the small blocks of autogeneic cartilage, or plugging bio-protein jelly after cartilage replanting. Each experimental group was handled with two methods in two sides of costal cartilage. No operation was performed in control group. All the rabbits were sacrificed 16 weeks after operation. The appearance of thoracic cage and new-formed tissue at the defect site were examined grossly. Haematoxylin-eosin staining was performed to evaluate the characteristics of new-formed tissues and biomechanical detection was used to measure intension of new-formed tissues.

RESULTSThe appearance of thoracic cage was normal in every experimental group. Histological study showed that the defect was filled with abundant fibrous tissue in each group. The chipping of cartilage survived effectively with little proliferation. Biomechanical detection showed that the intension of new-formed tissue in the non-replanted group [(193.92 +/- 41.41) N] was obviously less than that in the replanted group [(318.88 +/- 28.28) N], or bio-protein jelly group [(301.00 +/- 39.52) N], or control group [(300.54 +/- 38.35) N] (P < 0.01). Furthermore, there was no statistical difference between the latter three groups (P > 0.05).

CONCLUSIONSAlthough replanting the chipping of cartilage can't promote reparative regeneration of hyaline cartilage, it can definitively strengthen the intensity of new-formed tissue, reinforce thoracic stability. It may also indirectly decrease the incidence rate of postoperative chest wall deformity.