Abstract:

BACKGROUND: The developmental dislocation of the hip is a kind of common orthopaedics deformity. Function practice is the main measure to prevent articular adhesion after operation. But the right time choice depends on the healing degree of the capsule of hip joint.
OBJECTIVE: To observe the morphology of hip joint capsule cut-healing model of the rabbits and the expression of matrix metalloproteinase 2 after chitosan induction, so as to explore the healing mechanism of hip capsule.
METHODS: New Zealand white rabbit was used to establish the hip joint capsule cut-healing model, the left hip joint capsule (experimental group) was injected with 1 mL chitosan before closure, and the right hip joint capsule (control group) was closed after cutting without chitosan induction. The capsules were immediately obtained after executed the rabbit, then the collagen analysis was performed by Masson staining, and the expression of matrix metalloproteinase 2 was detected by ABC immunohistochemical method.
RESULTS AND CONCLUSION: The collagen staining showed that collagen distribution and arrangement in these two groups were gradually changed to the better trend from 3 days to 28 days, but the early edema and fracture were obvious. The integrity of the collagen fiber morphology, the fracture gap and arrangement dense and regularity level in the control group were worse than those in the experimental group. Detection of the matrix metalloproteinase 2 showed that the expression of matrix metalloproteinase 2 was positive in both groups and grown stronger with the time increasing, but not fully synchronized. The expression of matrix metalloproteinase 2 in the control group was decreased at 7 days after operation and finally weaker than that in the experimental group, while the expression in the experimental group was continued increasing and stronger than that in the control group, excepted for the 3rd day after operation. Matrix metalloproteinase 2 participates in the reconstruction process through digesting degenerated collagen, and the reconstruction process should be longer than 28 days. Chitosan can promote healing process through delaying tissue necrosis degeneration and depressing inflammatory reaction.