Regenerative rotator cuff repair in a clinically relevant chronic disease model

ABSTRACT Rotator cuff repairRCRis a common first line surgical solution to symptomatic rotator cuff injurywith overRCRs performed annuallyand growing at a rate ofUnfortunatelyof the cases are complicated by failure and re tear of the repaired tendonwhich commonly results in a significant reduction in activities of daily livingworkand or sports and recreation for the patient due to pain and restricted movementFailed rotator cuff repairs stem from issues associated with suture retentionmaintaining the correct anatomic position of the tendon when reattachedand the lack of enduring mechanical support for the shoulder and repaired tendonwhich is necessary to allow adequate healing time after the surgical procedureThese issues are even more problematic for severe or chronic tears where muscle atrophyfatty infiltrationand retraction from the anatomic insertion site complicate tendon repairsIn this projectwe propose a high performance textile based implant designed to address the deficiencies of current RCRThe innovation of the project is twofoldthe scaffold is designed to mimic the mechanical properties of native tendon andthe partially resorbable structure and the specific utilization of resorbable and non resorbable yarns minimizes the potential generation of particulate debrismaintains discreteinterconnected zones to promote cell infiltrationdifferentiationand integration with both the tendon and bone tissues in their respective zonesWe aim to further the development of this high performance scaffold by varying weaving parameters in order to maximize the biological propertieswhile retaining the mechanical properties of native tendonIn Aimfiber diameter and yarn spacing will be modulated to create implants with different architectures in four combinations that will be studied in vitro via explant cultureand assessed via histological and biomechanical analysisIn Aimthe optimized scaffold will be assessed in an clinically relevant ovine model of chronic tendinopathywhich we have shown to mimic the chronic human conditionAdditionallyby attaching the implant to a completely transected tendonthis model also tests the efficacy of the implant under a severe clinical condition of a complete mechanical deficitThe control cohort will be repaired using advanced suture techniques onlywhich is the current standard of careAtmonthsmobility restorationtendon and bone integrationand repair strength will be assessed via biomechanical testing and histological analysisThe goal of this study is to further the development of a new implant specifically tailored to meet the disparate requirements for both tendon and bone incorporation during repair of severely torn rotator cuff tendonsWe anticipate that this will lead to improved functionality of the injured cuff in these challenging cases and ultimately improve long term clinical outcomes NARRATIVE Rotator cuff repairs suffer from high failure rates due to tendon re tear despite many advances in surgical proceduresTo address this problemparticularly for severe and clinically challenging caseswe propose a high performancetextile based implant that provides mechanical support while promoting healing and integration with native tissuesThe ultimate objective of this project is to refine the properties of the device and then to assess its potential for improving rotator cuff repair in a clinically relevant chronic tendiopathy animal model