Department of Mechanical Engineering & Materials Science, Washington University, St. Louis, Missouri.
Department of Biomedical Engineering, Washington University, St. Louis, Missouri.
J Bone Joint Surg Am. 2023 Feb 1;105(3):223-230. doi: 10.2106/JBJS.22.00064. Epub 2022 Dec 2.
Simple elbow dislocation occurs at an incidence of 2.9 to 5.21 dislocations per 100,000 person-years, with as many as 62% of these patients experiencing long-term elbow joint contracture, stiffness, and/or pain. Poor outcomes and the need for secondary surgical intervention can often be prevented nonoperatively with early or immediate active mobilization and physical therapy. However, immobilization or limited mobilization may be necessary following trauma, and it is unknown how different periods of immobilization affect pathological changes in elbow joint tissue and how these changes relate to range of motion (ROM). The purpose of this study was to investigate the effects of varying the initiation of free mobilization on elbow ROM and histological features in an animal model of elbow posttraumatic joint contracture.
Traumatic elbow dislocation was surgically induced unilaterally in rats. Injured forelimbs were immobilized in bandages for 3, 7, 14, or 21 days; free mobilization was then allowed until 42 days after injury. Post-mortem joint ROM testing and histological analysis were performed. One-way analysis of variance was used to compare ROM data between control and injured groups, and Pearson correlations were performed between ROM parameters and histological outcomes.
Longer immobilization periods resulted in greater ROM reductions. The anterior and posterior capsule showed increases in cellularity, fibroblasts, adhesions, fibrosis, and thickness, whereas the measured outcomes in cartilage were mostly unaffected. All measured histological characteristics of the capsule were negatively correlated with ROM, indicating that higher degrees of pathology corresponded with less ROM.
Longer immobilization periods resulted in greater ROM reductions, which correlated with worse histological outcomes in the capsule in an animal model of posttraumatic elbow contracture. The subtle differences in the timing of ROM and capsule tissue changes revealed in the present study provide new insight into the distinct timelines of biomechanical changes as well as regional tissue pathology.
This study showed that beginning active mobilization 3 days after injury minimized posttraumatic joint contracture, thereby supporting an immediate-motion clinical treatment strategy (when possible). Furthermore, uninjured but pathologically altered periarticular tissues near the injury location may contribute to more severe contracture during longer immobilization periods as the disease state progresses.
单纯性肘关节脱位的发病率为每 10 万人 2.9 至 5.21 例脱位，多达 62%的患者会出现长期肘关节挛缩、僵硬和/或疼痛。通过早期或立即主动活动和物理治疗，通常可以避免手术治疗不佳的结果和对二次手术的需求。然而，受伤后可能需要固定或限制活动，目前尚不清楚不同固定时间如何影响肘关节组织的病理变化，以及这些变化与关节活动度（ROM）的关系。本研究旨在探讨在创伤后肘关节关节挛缩动物模型中，改变自由活动开始时间对肘关节 ROM 和组织学特征的影响。
手术诱导大鼠单侧肘关节脱位。受伤的前肢用绷带固定 3、7、14 或 21 天；然后允许自由活动，直到受伤后 42 天。进行关节 ROM 测试和组织学分析。使用单因素方差分析比较对照组和损伤组的 ROM 数据，并对 ROM 参数和组织学结果进行 Pearson 相关性分析。
固定时间越长，ROM 减少越大。前囊和后囊的细胞数量、成纤维细胞、粘连、纤维化和厚度增加，而软骨的测量结果基本不受影响。囊的所有测量组织学特征均与 ROM 呈负相关，表明病理学程度越高，ROM 越低。
固定时间越长，ROM 减少越大，这与创伤后肘关节挛缩动物模型中囊的组织学结果较差相关。本研究中揭示的 ROM 和囊组织变化时间上的细微差异为生物力学变化和局部组织病理学的不同时间线提供了新的见解。
本研究表明，受伤后 3 天开始主动活动可最大限度地减少创伤后关节挛缩，从而支持即时运动的临床治疗策略（如果可能）。此外，受伤部位附近未受伤但病理改变的关节周围组织可能会在更长的固定时间内导致更严重的挛缩，因为疾病状态会逐渐进展。
