Rotator cuff tendon to bone insertion site healing

描述（由申请人提供）：在受伤后，肩袖肌腱愈合回骨的能力是有限的，据报道，在20-70%的病例中，手术修复的肩袖撕裂不完全愈合。许多外科医生无法控制的因素导致愈合潜力有限，包括患者年龄、撕裂大小和从损伤到修复的时间。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。关于外科修复技术的研究很多，包括修复方式、缝合方法的强度、锚定技术的安全性等方面的研究。令人惊讶的是，虽然术后康复方案通常被认为对愈合过程的基本机制和由此产生的功能有很大的影响，但很少有关于这一主题的数据可以指导临床医生。因此，大多数术后方案都是基于特定临床医生的轶事经验。在我们实验室最近的一项研究中，我们开发了一种动物模型，可以仔细评估肩袖肌腱到骨插入部位的愈合情况。使用该模型，本研究的总体目标是研究固定和再活动后肩袖肌腱到骨插入部位的愈合过程。将测量生物力学和结构特性，以评估术后方案对愈合的影响。此外，将进行组织学和分子生物学评估，以开始阐明生物力学和结构特性改变的机制。具体目的是：(1)在肌腱至骨插入部位损伤和修复后，在给定的固定时间内改变固定时间。(2)肌腱至骨止点损伤和修复后，在给定的固定时间内改变固定时间。我们认为，在足够的固定期之后，长时间的再活化期将使肌腱纤维充分融入骨骼，并表达适当的ECM蛋白以重新形成插入点，从而使插入点具有更好的机械性能和更整齐的胶原纤维。

DESCRIPTION (provided by applicant): The ability of rotator cuff tendons to heal back to bone following injury is limited and incomplete healing 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. Much research has been done on surgical repair technique including studies related to repair approach, strength of suturing methods, and security of anchoring techniques. Surprisingly, while post-operative rehabilitation protocols are generally understood to have a great influence on the fundamental mechanisms of the healing process and on the resulting function, very little data is available on this topic to guide the clinician. As a result, most post-operative protocols are based on anecdotal experiences of particular clinicians. In a recent study in our laboratory, we developed an animal model in which the healing of the rotator cuff tendon to bone insertion site could be carefully evaluated. Using this model, the overall objective of the current study is to investigate the healing process of the rotator cuff tendon to bone insertion site subject to immobilization and remobilization. Biomechanical and structural properties will be measured to evaluate the effect of the post-operative protocol on healing. In addition, histologic and molecular biologic assessments will be performed to begin to elucidate the mechanisms through which biomechanical and structural properties were altered. The Specific Aims are: (1) following tendon to bone insertion site injury and repair, vary the immobilization period for a given set of remobilization period. (2) Following tendon to bone insertion site injury and repair, vary the remobilization period for a given set of immobilization period. We believe that a long remobilization period, following a sufficient immobilization period, will allow adequate integration of tendon fibers into bone and expression of appropriate ECM proteins to re-form the insertion site resulting in an insertion site with improved mechanical properties and more aligned collagen fibers.