Yukitoshi Kaizawa1, Jacinta Leyden1, Anthony W Behn2, U Serdar Tulu3, Austin Franklin1, Zhen Wang1, Geoffrey Abrams2, James Chang1, Paige M Fox4. 1. Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University Medical Center, Palo Alto, CA; Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA. 2. Department of Orthopaedic Surgery, Stanford University School of Medicine, Palo Alto, CA. 3. Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University Medical Center, Palo Alto, CA. 4. Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University Medical Center, Palo Alto, CA; Division of Plastic and Reconstructive Surgery, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA. Electronic address: pfox@stanford.edu.
Abstract
PURPOSE: Poor healing of the tendon-bone interface (TBI) after rotator cuff (RTC) tears leads to high rates of recurrent tear following repair. Previously, we demonstrated that an injectable, thermoresponsive, type I collagen-rich, decellularized human tendon-derived hydrogel (tHG) improved healing in an acute rat Achilles tendon injury model. The purpose of this study was to investigate whether tHG enhances the biomechanical properties of the regenerated TBI in a rat model of chronic RTC injury and repair. METHODS: Tendon hydrogel was prepared from chemically decellularized human cadaveric flexor tendons. Eight weeks after bilateral resection of supraspinatus tendons, repair of both shoulders was performed. One shoulder was treated with a transosseous suture (control group) and the other was treated with a transosseous suture plus tHG injection at the repair site (tHG group). Eight weeks after repair, the TBIs were evaluated biomechanically, histologically, and via micro-computed tomography (CT). RESULTS: Biomechanical testing revealed a larger load to failure, higher stiffness, higher energy to failure, larger strain at failure, and higher toughness in the tHG group versus control. The area of new cartilage formation was significantly larger in the tHG group. Micro-CT revealed no significant difference between groups in bone morphometry at the supraspinatus tendon insertion, although the tHG group was superior to the control. CONCLUSIONS: Injection of tHG at the RTC repair site enhanced biomechanical properties and increased fibrocartilage formation at the TBI in a chronic injury model. CLINICAL RELEVANCE: Treatment of chronic RTC injuries with tHG at the time of surgical treatment may improve outcomes after surgical repair.
PURPOSE: Poor healing of the tendon-bone interface (TBI) after rotator cuff (RTC) tears leads to high rates of recurrent tear following repair. Previously, we demonstrated that an injectable, thermoresponsive, type I collagen-rich, decellularized human tendon-derived hydrogel (tHG) improved healing in an acute ratAchilles tendon injury model. The purpose of this study was to investigate whether tHG enhances the biomechanical properties of the regenerated TBI in a rat model of chronic RTC injury and repair. METHODS: Tendon hydrogel was prepared from chemically decellularized human cadaveric flexor tendons. Eight weeks after bilateral resection of supraspinatus tendons, repair of both shoulders was performed. One shoulder was treated with a transosseous suture (control group) and the other was treated with a transosseous suture plus tHG injection at the repair site (tHG group). Eight weeks after repair, the TBIs were evaluated biomechanically, histologically, and via micro-computed tomography (CT). RESULTS: Biomechanical testing revealed a larger load to failure, higher stiffness, higher energy to failure, larger strain at failure, and higher toughness in the tHG group versus control. The area of new cartilage formation was significantly larger in the tHG group. Micro-CT revealed no significant difference between groups in bone morphometry at the supraspinatus tendon insertion, although the tHG group was superior to the control. CONCLUSIONS: Injection of tHG at the RTC repair site enhanced biomechanical properties and increased fibrocartilage formation at the TBI in a chronic injury model. CLINICAL RELEVANCE: Treatment of chronic RTC injuries with tHG at the time of surgical treatment may improve outcomes after surgical repair.
Authors: Ryan C Locke; Eden M Ford; Karin G Silbernagel; April M Kloxin; Megan L Killian Journal: Tissue Eng Part C Methods Date: 2020-10 Impact factor: 3.273