Rotator cuff healing using demineralized cancellous bone matrix sponge interposition compared to standard repair in a preclinical canine model.

This Level II study assessed clinically relevant outcomes for repair of large, retracted infraspinatus tendons (ISTs) using a demineralized bone matrix (DBM) sponge (FlexiGraft) hydrated in platelet-rich plasma (PRP) versus direct repair in a validated canine model. Adult research dogs (n = 10) were used. The IST was transected in each shoulder (n = 20) and randomized to direct repair or repair with DBM-PRP interposition at 4 weeks posttransection. At 12 weeks postrepair, dogs were sacrificed, and the repair evaluated by magnetic resonance imaging (MRI), histology, and biomechanical testing. MRI and histology scores were significantly (p < 0.05) better in the DBM-PRP shoulders. Biomechanical testing revealed significantly improved strength of the DBM-PRP repairs at 5 and 10 mm of displacement, as well as for ultimate failure load. In this canine model of retracted IST repair, DBM-PRP sponge hydrated in PRP was considered safe and effective. In addition, use of DBM-PRP was associated with improved MRI and histologic appearance, and improved strength compared to direct repair.

CLINICAL SIGNIFICANCE: Based on reported failure rates for repair of large, retracted rotator cuff tears, improving tendon-to-bone healing is critical. Use of DBM combined with PRP shows potential for addressing this critical clinical need. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:906-912, 2018.