Trudel Guy, Zhou Jian, Uhthoff Hans K, Laneuville Odette
Bone and Joint Laboratory, University of Ottawa, Ottawa, ON, Canada.
Clin Orthop Relat Res. 2008 May;466(5):1239-44. doi: 10.1007/s11999-008-0181-z. Epub 2008 Feb 26.
Prolonged immobilization reduces passive range of motion of joints creating joint contractures. Whether and to what extent these iatrogenic contractures can be reduced is unknown. We raised three questions using an animal model: What degree of contracture remains at the end of a defined remobilization period? Do contractures in sham-operated and immobilized joints differ? What is the contribution of the posterior knee capsule in limiting knee extension? We immobilized one knee of 11 adult male rats in flexion to induce a joint contracture; 10 control animals underwent a sham operation. After 8 weeks, the internal fixation device was removed, and the animals were allowed to resume unrestricted activity for 4 weeks at the end of which the knee range of motion was measured with standardized torques. The mean flexion contracture was higher in the immobilized group (51.9 degrees +/- 2.8 degrees ) than in the sham-operated group (18.9 degrees +/- 2.1 degrees ). Eighty-eight percent of the contractures remained in the immobilized group after dividing skin and muscle, suggesting an important contribution of the posterior knee capsule in limiting knee mobility. Based on our preliminary study the range of motion of rat knees immobilized for 8 weeks remained substantially reduced after a 4-week period of unassisted remobilization.
长期制动会降低关节的被动活动范围，从而导致关节挛缩。这些医源性挛缩能否以及在何种程度上得以减轻尚不清楚。我们使用动物模型提出了三个问题：在规定的重新活动期结束时，挛缩程度会残留多少？假手术组和制动组的关节挛缩情况是否不同？后膝囊在限制膝关节伸展方面起到了什么作用？我们将11只成年雄性大鼠的一侧膝关节固定于屈曲位以诱发关节挛缩；10只对照动物接受假手术。8周后，取出内固定装置，让动物在无限制活动状态下恢复4周，之后用标准扭矩测量膝关节活动范围。制动组的平均屈曲挛缩（51.9度±2.8度）高于假手术组（18.9度±2.1度）。在分离皮肤和肌肉后，制动组88%的挛缩依然存在，这表明后膝囊在限制膝关节活动方面起到了重要作用。基于我们的初步研究，大鼠膝关节在制动8周后，经过4周的自主重新活动期，其活动范围仍大幅受限。
