Bridging Repair of Large Rotator Cuff Tears Using a Multilayer Decellularized Tendon Slices Graft in a Rabbit Model

Purpose The purpose of this study was to evaluate the efficacy of an extracellular matrix scaffold with multilayer decellularized tendon slices (MDTSs) for reconstructing large rotator cuff tears in a rabbit model. Methods Large defects in the infraspinatus tendons were created bilaterally in 36 rabbits. The graft group underwent bridging repair of the defects with the MDTSs grafts from Achilles tendons of adult beagle dogs, and the control group underwent repair with the autologous excised tendon. Specimens underwent histologic observation, biomechanical testing, and microcomputed tomography analysis at 2, 4, and 8 weeks after surgery. Results Histologic analysis confirmed that the MDTSs graft promoted cell ingrowth and tissue integration, and fibrocartilage and Sharpey fibers formed at the enthesis at 8 weeks. Accordingly, the MDTSs graft generated a histologic appearance similar to that of the autogenous tendon graft. Mechanical testing revealed a significant increase of the regenerated tendons in ultimate load and stiffness from 4 to 8 weeks postoperatively, which was similar to autologous tendon repair. Microcomputed tomography analysis demonstrated that the MDTSs graft promoted bone formation at the tendon-bone insertion, thus improving the mechanical properties of the repair tendon. Conclusions The MDTSs graft used to bridge large rotator cuff defects in a rabbit model promoted host cell ingrowth, enhanced the remodeling of regenerated tendon, and promoted fibrocartilage formation, thus improving the biomechanical properties of the repaired tendon. This study thereby provides fundamental information for rotator cuff regeneration with the MDTSs graft. Clinical Relevance Rotator cuff regeneration using MDTSs grafts is a promising procedure for large rotator cuff tears. The purpose of this study was to evaluate the efficacy of an extracellular matrix scaffold with multilayer decellularized tendon slices (MDTSs) for reconstructing large rotator cuff tears in a rabbit model. Large defects in the infraspinatus tendons were created bilaterally in 36 rabbits. The graft group underwent bridging repair of the defects with the MDTSs grafts from Achilles tendons of adult beagle dogs, and the control group underwent repair with the autologous excised tendon. Specimens underwent histologic observation, biomechanical testing, and microcomputed tomography analysis at 2, 4, and 8 weeks after surgery. Histologic analysis confirmed that the MDTSs graft promoted cell ingrowth and tissue integration, and fibrocartilage and Sharpey fibers formed at the enthesis at 8 weeks. Accordingly, the MDTSs graft generated a histologic appearance similar to that of the autogenous tendon graft. Mechanical testing revealed a significant increase of the regenerated tendons in ultimate load and stiffness from 4 to 8 weeks postoperatively, which was similar to autologous tendon repair. Microcomputed tomography analysis demonstrated that the MDTSs graft promoted bone formation at the tendon-bone insertion, thus improving the mechanical properties of the repair tendon. The MDTSs graft used to bridge large rotator cuff defects in a rabbit model promoted host cell ingrowth, enhanced the remodeling of regenerated tendon, and promoted fibrocartilage formation, thus improving the biomechanical properties of the repaired tendon. This study thereby provides fundamental information for rotator cuff regeneration with the MDTSs graft.