Establishing a rabbit model of knee joint extension contracture / 中华物理医学与康复杂志

ABSTRACT

Objective To establish a model of knee joint extension contracture in New Zealand white rab-bits, and to lay the experimental foundation for further studies on the pathogenesis and treatment of joint contractures. Methods Thirty male New Zealand white rabbits with mature bones were randomly divided into 6 groups. The left knee joints of the immobilization groups ( 5 groups of 5 rats each) were fixed in extension for 1, 2, 4, 6 or 8 weeks. There was also a control group. At the end of each period the plaster was demolished and the level of transforming growth factor-β1 ( TGF-β1) in joint cavities, the degree of total contracture, myogenic contracture, arthrogenic con-tracture, and the thickness of the posterior joint capsules were measured. The significance of the differences between the immobilized groups and the control group was compared using one-way analysis. Results The level of TGF-β1 in the joint fluid differed significantly among the 6 groups. The differences in the degree of total contracture among the control group, one-week, two-week and four-week groups were also significant. The average degree of the myogenic contracture in the one-week group was significantly different from the other 5 groups' averages. The average myogenic contracture was also of significantly different between the two-week group and the control group. The degree of arthro-genic contracture was significantly different among the groups except for between the 6-week and 8-week groups. The average joint capsule thickness was significantly different among all of the groups except for between the control group and the one-week group. Conclusion This technique for modeling knee extending contracture using New Zealand white rabbits is simple and practical. It provides a better animal model for studying the mechanism of knee joint con-tracture and related treatment strategies and can be used for further exploration of the occurrence and recovery of knee contractures.