Rotator cuff tendon to bone insertion site healing

描述(申请人提供)：肩袖肌腱在受伤后愈合回到骨骼的能力是有限的，据报道，在人类中，手术修复的肩袖撕裂有20%-70%的病例是不完全愈合的。许多外科医生无法控制的因素导致了有限的愈合潜力，包括患者的年龄、泪水大小和从受伤到修复的时间。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。对手术修复技术进行了大量的研究，包括修复途径、缝合方法的强度、锚固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所产生的功能有很大的影响，但在这个主题上指导临床医生的数据很少。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，在该模型中，可以仔细评估肩袖肌腱到骨附着点的愈合情况。利用这一模型，本研究的总体目标是研究肩袖肌腱在固定和再动员情况下从肩袖肌腱到骨植入部位的愈合过程。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，还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。其具体目的是：(1)随着肌腱到骨的附着部位的损伤和修复，改变固定时间，以确定一套固定时间。(2)肌腱-骨结合部位损伤修复后，根据固定时间的不同，改变固定时间。我们认为，在足够的固定期之后，较长的再动员时间将允许肌腱纤维充分整合到骨中，并表达适当的ECM蛋白以重新形成插入部位，从而产生具有更好的机械性能和更多排列的胶原纤维的插入部位。

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.