Amniotic membrane improves force production after repair of a massive rotator cuff tear

Abstract

Rotator cuff tears are a common cause of upper extremity disability, with nearly 250,000 surgical repairs performed annually. Chronically torn rotator cuff muscles display profound muscle atrophy, fibrosis and accumulation of fat in and around muscle fibers. Even after undergoing surgical repair, many patients continue to have persistent muscle atrophy, and re‐tear rates are 40% or more. Identifying novel therapies that can promote muscle regeneration after rotator cuff repair could lead to substantial improvements in our ability to treat chronic rotator cuff tears. Human amniotic‐derived grafts are a type of allograft that is thought to have the potential to improve tissue regeneration, although the mechanism of these products is not well characterized and to our knowledge has not been studied in respect to rotator cuff regeneration. Using a preclinical rotator cuff tear model in rats, our objective was to determine the efficacy of human amniotic derived grafts on rotator cuff muscle regeneration. To accomplish this, we induced a chronic rotator cuff tear for 30 days and then repaired the tear in the presence or absence of the human amniotic stem cell graft. We then analyzed the contractile function of muscle fibers from control and treated muscles. Muscle cross‐sectional area (CSA), maximum isometric force (Fo) and the force per cross‐sectional area, or specific force (sFo) were recorded from muscle fibers isolated from each of these groups. We hypothesized that treatment with human amniotic cell graft would improve sFo in rats compared to rats without these grafts. The CSA of the amniotic membrane repair group was 53% greater than the control repair group (p<0.01), and the Fo was also 55% higher with membrane supplementation (p<0.01). Further, sFo of the membrane repair group was 13% larger than the control repair (p=0.02). Combined, the augmentation of chronic rotator cuff repair surgery with a human amniotic derived graft in rats markedly improved muscle function. Based on this promising preclinical data, further study of human amniotic stem cell grafts in patients with chronic rotator cuff tears in warranted.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.