Bone Marrow Aspirate Concentrate Combined With an Appropriate Carrier Effectively Promotes Bone-Tendon Interface Healing in a Rabbit Model of Chronic Rotator Cuff Tear

Background: The efficacy of bone marrow aspirate concentrate (BMAC) in promoting bone-tendon interface (BTI) healing without any carriers remains a subject of debate. Purpose: To evaluate BMAC effects with different carriers on tendon regeneration in a rabbit model of chronic rotator cuff tear. Study Design: Controlled laboratory study. Methods: In vitro, the amount of growth factor and the differentiation potential of BMAC with different carriers (polydeoxyribonucleotide [PDRN] and atelocollagen [ATC]) were assessed. In vivo, 64 rabbits were randomly allocated into 4 groups. Different materials were injected into the repair site according to the allocated group: control, saline; BMAC, BMAC and saline; BMAC-PDRN, BMAC with PDRN; BMAC-ATC, BMAC with ATC (n = 16 in each). Genetic and histologic analyses were conducted at 4 and 12 weeks after repair, while biomechanical evaluations were performed at 12 weeks after repair. Results: In vitro, the degree of multilineage differentiation was much stronger using BMAC with ATC as compared with administration of BMAC alone or BMAC with PDRN ( P < .001). In vivo, the BMAC-ATC group had the highest levels of aggrecan expression, bone morphogenetic protein 2, and collagen type I alpha 1 among all groups (all P < .001) at 4 weeks after repair. Furthermore, the BMAC-ATC group showed collagen fiber continuity, denser collagen fibers, and more mature BTI as compared with the other groups (all P < .001) at 12 weeks after repair. Concurrently, the BMAC-ATC group also demonstrated significantly higher load-to-failure versus the remaining groups (all P < .001) at 12 weeks after repair. Conclusion: Local application of BMAC without appropriate carriers could not enhance BTI healing. However, BMAC with 2 different carriers effectively accelerated BTI healing, particularly in the ATC environment. Therefore, the combination of BMAC and ATC may act as a powerful biological agent to promote healing after rotator cuff repair in a chronic rotator cuff tear model using rabbits. Clinical Relevance: Local application of BMAC without appropriate carriers could not enhance BTI healing. However, the combination of BMAC and ATC may synergistically promote rotator cuff tendon healing.