Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
J Shoulder Elbow Surg. 2019 Apr;28(4):654-664. doi: 10.1016/j.jse.2018.08.044. Epub 2018 Dec 4.
Chronic massive rotator cuff tears heal poorly and often retear. This study investigated the effect of adipose-derived stem cells (ADSCs) and transforming growth factor-β3 (TGF-β3) delivered in 1 of 2 hydrogels (fibrin or gelatin methacrylate [GelMA]) on enthesis healing after repair of acute or chronic massive rotator cuff tears in rats.
Adult male Lewis rats underwent bilateral transection of the supraspinatus and infraspinatus tendons with intramuscular injection of botulinum toxin A (n = 48 rats). After 8 weeks, animals received 1 of 8 interventions (n = 12 shoulders/group): (1) no repair, (2) repair only, or repair augmented with (3) fibrin, (4) GelMA, (5) fibrin + ADSCs, (6) GelMA + ADSCs, (7) fibrin + ADSCs + TGF-β3, or (8) GelMA + ADSCs + TGF-β3. An equal number of animals underwent acute tendon transection and immediate application of 1 of 8 interventions. Enthesis healing was evaluated 4 weeks after the repair by microcomputed tomography, histology, and mechanical testing.
Increased bone loss and reduced structural properties were seen in chronic compared with acute tears. Bone mineral density of the proximal humerus was higher in repairs of chronic tears augmented with fibrin + ADSCs and GelMA + ADSCs than in unrepaired chronic tears. Similar improvement was not seen in acute tears. No intervention enhanced histologic appearance or structural properties in acute or chronic tears.
Surgical repair augmented with ADSCs may provide more benefit in chronic tears compared with acute tears, although there was no added benefit to supplementing ADSCs with TGF-β3.
慢性巨大肩袖撕裂愈合不良，常再次撕裂。本研究探讨了在急性或慢性巨大肩袖撕裂修复后，以 2 种水凝胶（纤维蛋白或明胶甲基丙烯酰（GelMA）中的 1 种递送脂肪来源干细胞（ADSCs）和转化生长因子-β3（TGF-β3）对腱骨愈合的影响。
成年雄性 Lewis 大鼠双侧切断冈上肌和冈下肌肌腱，并在肌肉内注射肉毒毒素 A（n = 48 只大鼠）。8 周后，动物接受以下 8 种干预措施中的 1 种（n = 12 只肩/组）：（1）不修复，（2）仅修复，或修复后（3）用纤维蛋白增强，（4）用 GelMA 增强，（5）纤维蛋白+ADSCs，（6）GelMA+ADSCs，（7）纤维蛋白+ADSCs+TGF-β3，或（8）GelMA+ADSCs+TGF-β3。相等数量的动物进行了急性肌腱切断术，并立即应用了 8 种干预措施中的 1 种。修复后 4 周，通过 microCT、组织学和力学测试评估腱骨愈合。
与急性撕裂相比，慢性撕裂中可见骨丢失增加和结构特性降低。慢性撕裂中，纤维蛋白+ADSCs 和 GelMA+ADSCs 增强修复的肱骨近端骨密度高于未修复的慢性撕裂。在急性撕裂中没有看到类似的改善。在急性或慢性撕裂中，没有干预措施能增强组织学表现或结构特性。
与急性撕裂相比，ADSCs 增强的手术修复可能在慢性撕裂中提供更多益处，尽管补充 TGF-β3 对 ADSCs 没有额外益处。
