McKinley Todd O, Rudert M James, Koos Daniel C, Brown Thomas D
Department of Orthopaedic Surgery, University of Iowa, Iowa City, IA, USA.
Clin Orthop Relat Res. 2004 Jun(423):44-51. doi: 10.1097/01.blo.0000131639.89143.26.
The etiology of posttraumatic arthritis is understood poorly but it clearly has a pathomechanical component. Posttraumatic arthritis likely results from irreversible cartilage damage sustained at the time of injury and chronic cartilage overloading resulting from articular incongruity and instability. However, the relative importance of instability and incongruity is unknown. Clinical studies show that the hip, knee, and ankle tolerate incongruity differently. However, all three joints poorly tolerate instability. Basic mechanical studies have shown that static loading of articular surface incongruities have caused relatively modest increases in contact pressure. However, static testing poorly replicates normal viscoelastic properties of cartilage, which may mask important transient stress elevations that occur during motion. Static tests also ignore potential abnormal loads that may accumulate throughout a motion cycle. We review the clinical and basic scientific evidence linking incongruity and instability to posttraumatic arthritis. Preliminary data from a newly developed dynamic ankle testing device are presented. Dynamic testing allows measurement of transient contact loads and loading rates that occur through the entire motion cycle and it opens the door to measure mechanical abnormalities associated with instability.
创伤后关节炎的病因目前了解甚少，但显然它有一个病理力学组成部分。创伤后关节炎可能源于受伤时所遭受的不可逆软骨损伤以及关节不协调和不稳定导致的慢性软骨过度负荷。然而，不稳定和不协调的相对重要性尚不清楚。临床研究表明，髋关节、膝关节和踝关节对不协调的耐受程度不同。然而，这三个关节对不稳定的耐受都很差。基础力学研究表明，关节表面不协调的静态负荷只会使接触压力相对适度增加。然而，静态测试很难复制软骨的正常粘弹性特性，这可能掩盖运动过程中出现的重要瞬时应力升高。静态测试还忽略了在整个运动周期中可能累积的潜在异常负荷。我们回顾了将不协调和不稳定与创伤后关节炎联系起来的临床和基础科学证据。还展示了一种新开发的动态踝关节测试装置的初步数据。动态测试能够测量整个运动周期中出现的瞬时接触负荷和负荷率，为测量与不稳定相关的力学异常打开了大门。
