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 ( < .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 < .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 < .001) at 12 weeks after repair. Concurrently, the BMAC-ATC group also demonstrated significantly higher load-to-failure versus the remaining groups (all < .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.