Rotator cuff tendon to bone insertion site healing

肩袖肌腱在受伤后恢复到骨的能力是有限的， 据报道，在20-70%的病例中，手术修复了人类的肩袖撕裂。外界诸多因素 包括患者年龄、撕裂大小和时间在内的外科医生的控制力导致了有限的愈合潜力 从受伤到修复然而，外科医生可以控制的两个重要因素是手术修复 技术和术后康复方案。虽然对外科修复已经做了很多研究， 技术，令人惊讶的是，很少有关于肌腱术后康复方案的数据， 肩部的骨修复可用于指导临床医生。因此，目前的临床趋势是 修复后不久被动活动肩关节，目前失败率很高， 一直依赖于手部肌腱愈合的数据。然而，我们的动物模型的数据， 其他研究表明，肌腱对活动的反应可能是不同的，当愈合到骨，而不是 肌腱我们最近开发了一种动物模型，在该模型中， 插入部位可以作为术后活动水平函数进行仔细评估。固定化 发现导致更好的愈合比笼子里的活动或锻炼，时间越长， 固定化，插入位点性质越好。基于这些结果，我们现在假设， 在足够的固定时间后的再活动将导致插入部位的机械和 与单独固定化相比的结构特性。需要一段时间的固定， “保护”插入位点并允许适当的细胞外基质（EGM）表达（例如，类型 和III胶原蛋白、聚集蛋白聚糖、核心蛋白聚糖和双糖蛋白聚糖），使得插入位点可以重新形成。因此， 重新动员的效果需要最短的固定时间。具体目标是：（1） 修复，连续或被动活动肩关节，并比较插入部位 修复后2、6、10、14、18和22周的力学、胶原纤维取向和ECM基因表达， 2)修复后，肩关节复位2、6和10周，然后再活动4、8和12周， 将插入位点力学、纤维方向和ECM基因表达与仅在 匹配修复后的时间点以及随着时间的推移，并且，由于固定已被证明可以减少 活动度，3）比较修复前和固定后即刻的被动活动度（ROM） 在3天、1周、2周和6周的再动员后，

The ability of rotator cuff tendons to heal back to bone following injury is limited, and failure of surgically repaired rotator cuff tears in humans has been reported in 20-70% of cases. Many factors outside of the surgeon's control contribute to the limited healing potential including patient age, tear size, and time from injury to repair. However, two important factors that are within the surgeon's control are surgical repair technique and post-operative rehabilitation protocol. While much research has been done on surgical repair technique, surprisingly, very little data in regard to post-operative rehabilitation protocols following tendon to bone repairs in the shoulder are available to guide clinicians. As a result, the current clinical trend to passively mobilize the shoulder shortly after repair, which is fraught with a high incidence of failure currently, has relied on data from tendon to tendon healing in the hand. However, data from our animal model and that of others indicates that the response of tendon to activity may be different when healing to bone rather than to tendon. We recently developed an animal model in which healing of the rotator cuff tendon to bone insertion site could be carefully evaluated as a function of post-operative activity level. Immobilization was found to result in better healing than either cage activity or exercise and the longer the period of immobilization, the better the insertion site properties. Based on these results, we now hypothesize that remobilization after a sufficient period of immobilization will lead to improved insertion site mechanical and structural properties compared to immobilization alone. A period of immobilization will be necessary to 'protect' the insertion site and to allow for appropriate extracellular matrix (EGM) expression (e.g., type and III collagen, aggrecan, decorin and biglycan) such that the insertion site can re-form. Thus, the positive effect of remobilization requires a minimum period of immobilization. The specific aims are: 1) Following repair, immobilize shoulders either continuously, or with passive motion, and compare insertion site mechanics, collagen fiber orientation and ECM gene expression at 2, 6, 10, 14, 18 and 22 weeks post-repair, 2) Following repair, immobilize shoulders for 2, 6 and 10weeks, then remobilize for 4, 8 and 12 weeks and compare insertion site mechanics, fiber orientation, and ECM gene expression to immobilization only at matching post-repair time points as well as over time, and, since immobilization has been shown to reduce range of motion, 3) Compare passive range of motion (ROM) prior to repair, immediately after immobilization has been discontinued, and after 3 ofays, 1, 2 and 6 weeks of remobilization.