Chimoto Eiichi, Hagiwara Yoshihiro, Ando Akira, Itoi Eiji
Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, Japan.
Ups J Med Sci. 2007;112(3):347-55. doi: 10.3109/2000-1967-207.
Contracture is defined as a decrease in both active and passive ranges of motion after immobilization. A fibrotic change of a capsule is suggested to be one of the main causes of the joint contracture. The goal of this study is to determine the effect of capsule on limiting the range of motion after immobilization.
We immobilized the knee joint of 35 rats with an internal fixator with the knee joint flexed at 150 degrees. The rats were sacrificed at 1, 2, 4, 6, 8, 12, and 16 weeks after surgery and the lower extremities were disarticulated at the hip joint. After extra-articular myotomies around the tibia and femur, x-rays were taken to measure the angles of extension of the knee joint under 3 different torques. The measurements were repeated after releasing the posterior capsule in order to observe their effects on knee motion.
Joint contracture was rapidly progressed until 8 weeks and advanced slowly after 8 weeks. After releasing the posterior capsule, both the immobilized and the control groups gained the angle of knee extension. The acquired angle in the immobilized group was significantly greater than in the control group after 4 weeks and became plateau after 8 weeks.
Joint contracture develops at the early stage of immobilization and progresses over time. The posterior capsule significantly contributes to the limitation in extension.
挛缩被定义为固定后主动和被动活动范围均减小。关节囊的纤维化改变被认为是关节挛缩的主要原因之一。本研究的目的是确定关节囊在固定后对限制活动范围的影响。
我们用内固定器将35只大鼠的膝关节固定在150度屈曲位。在术后1、2、4、6、8、12和16周处死大鼠，并在髋关节处离断下肢。在胫骨和股骨周围进行关节外肌肉切断术后，拍摄X线片以测量在3种不同扭矩下膝关节的伸展角度。在松解后关节囊后重复测量，以观察其对膝关节活动的影响。
关节挛缩在8周前迅速进展，8周后进展缓慢。松解后关节囊后，固定组和对照组的膝关节伸展角度均增加。固定组在4周后获得的角度明显大于对照组，并在8周后趋于平稳。
关节挛缩在固定早期出现并随时间进展。后关节囊对伸展受限有显著影响。
