Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa 52242, USA.
J Bone Joint Surg Am. 2011 Apr 6;93(7):640-7. doi: 10.2106/JBJS.J.00150.
Joint instability has long been empirically recognized as a leading risk factor for osteoarthritis. However, formal mechanistic linkage of instability to osteoarthritis development has not been established. This study aimed to support a clinically accepted, but heretofore scientifically unproven, concept that the severity and rapidity of osteoarthritis development in unstable joints is dependent on the degree of instability. In a survival rabbit knee model of graded joint instability, the relationship between the magnitude of instability and the intensity of cartilage degeneration was studied at the organ level in vivo.
Sixty New Zealand White rabbits received either complete or partial (medial half) transection of the anterior cruciate ligament or sham surgery (control) on the left knee. At the time that the animals were killed at eight or sixteen weeks postoperatively (ten animals for each treatment and/or test-period combination), the experimental knees were subjected to sagittal plane stability measurement, followed by whole-joint cartilage histological evaluation with use of the Mankin score.
Sagittal plane instability created in the partial transection group was intermediate between those in the complete transection and sham surgery groups. The partial and complete transection groups exhibited cartilage degeneration on the medial femoral and/or medial tibial surfaces. The average histological score (and standard deviation) for the medial compartment in the partial transection group (2.9 ± 0.9) was again intermediate, significantly higher than for the sham surgery group (1.9 ± 0.8) and significantly lower than for the complete transection group (4.5 ± 2.3). The average histological scores for the medial compartment in the partial transection group correlated significantly with the magnitude of instability, with no threshold effect being evident. The significance level of alpha was set at 0.05 for all tests.
The severity of cartilage degeneration increased continuously with the degree of instability in this survival rabbit knee model of graded instability.
关节不稳定长期以来被经验性地认为是骨关节炎的主要危险因素。然而，不稳定与骨关节炎发展之间的正式机制联系尚未建立。本研究旨在支持一种临床上公认但迄今为止尚未得到科学证实的概念，即不稳定关节中骨关节炎发展的严重程度和速度取决于不稳定的程度。在分级关节不稳定的存活兔膝关节模型中，在体内器官水平研究了不稳定程度与软骨退变强度之间的关系。
60 只新西兰白兔的左膝关节接受了完全或部分（内侧半）前交叉韧带切断术或假手术（对照组）。在手术后 8 或 16 周处死动物时（每种治疗和/或测试期组合各有 10 只动物），对实验膝关节进行矢状面稳定性测量，然后使用 Mankin 评分进行全关节软骨组织学评估。
部分切断组产生的矢状面不稳定介于完全切断组和假手术组之间。部分和完全切断组的内侧股骨和/或胫骨表面均出现软骨退变。部分切断组内侧间室的平均组织学评分（标准差）为 2.9 ± 0.9，再次处于中间水平，明显高于假手术组（1.9 ± 0.8），明显低于完全切断组（4.5 ± 2.3）。部分切断组内侧间室的平均组织学评分与不稳定程度显著相关，且无明显的阈值效应。所有检验的显著性水平均设为 0.05。
在这种分级不稳定的存活兔膝关节模型中，软骨退变的严重程度随着不稳定程度的增加而连续增加。
