Rotator Cuff Healing Using a Nanofiber Scaffold in Patients Greater Than 55 Years

1. INTRODUCTION This document is a protocol for a human research study. This study is to be conducted according to United States standards of Good Clinical Practice in accordance with applicable Federal regulations and institutional research policies and procedures. Despite numerous advancements in surgical techniques and over 250,000 procedures currently performed annually in the United States, failure of tendon healing following rotator cuff surgery occurs frequently with reports as high as 94%. Nonhealing can lead to persistent pain, poor outcomes, and a significant economic burden to society when revision surgery is required. Several factors have been associated with poor tendon healing with age greater than 60 years shown to be a significant risk factor due to diminishing vascularity at the bone tendon interface where the tear typically originates. While numerous techniques have been devised to improve fixation over the past several decades, very few have been developed to address or enhance the biology at the repair site. Rotium nanofiber is a recent FDA approved scaffold (FDA 510(K) #K183236) that has been shown to improve tendon healing to bone in animal studies. It works to mimic the extracellular matrix and helps concentrates and bind cells at the repair site providing a better organizational structure of the healing tissue. The purpose of the current study is to assess if use of the scaffold significantly improves rotator cuff healing and enhances strength in patients at higher risk of perioperative failure of the repair. 2. BACKGROUND INFORMATION AND SCIENTIFIC RATIONALE Rotator cuff tears are a frequent cause of shoulder pain and disability in the elderly population. Typically, when conservative measures fail, surgery is often advised. A successful clinical outcome is felt to be heavily predicated on healing of the tendon to the bone. Despite numerous surgical and technical advancements over the past two decades not all repairs heal, with re-tear, or failure-to-heal, remaining the number one complication associated with rotator cuff surgery. This in turn creates a hefty economic burden on society whereupon surgeries are being performed with poor eventual outcomes and ultimately wasted resources. While reasons for failure are multifactorial, a strong correlation has been associated with advancing age. In an observational study on the natural history of rotator cuff disease, patients younger than 50 years old rarely had rotator cuff tears whereas those greater than 60 had a statistically significant greater incidence of unilateral and bilateral tears. Advancing age is believed to alter and change the intrinsic properties of the tendon leading to stiffness, hypovascularity and overall impairment of the biology of tendon healing. Furthermore, when repairs fail, they typically do so within the first four months of surgery. Means, therefore, to enhance the zone of the repair by increasing the cellularity immediately following surgery may improve the overall healing and lessen failures. Recently, nanofiber scaffolds have demonstrated the ability to mimic the extracellular matrix and help structure, organize, and proliferate cellular material. They do so by working, in essence, like a sponge when incorporated into the repair site, helping to bind, organize, and promote cell migration. This in effect, creates a less haphazard arrangement and induces better organization of healing tissue at the cellular level. Rotium, is an FDA-approved, nonwoven, microfiber matrix composed of PLCL (poly L-lactide-co-caprolactone) and PGL (polyglycolide) that is indicated for use in rotator cuff repair to enhance healing at the bone tendon interface. The implant is inserted under the rotator cuff tendon and placed on top of the greater tuberosity at the time of surgery and typically positioned over a suture. In a recent animal study performed at Colorado State University, a nearly 75% increased strength of repair was demonstrated at twelve weeks in those tendons treated with the graft. This will be the first prospective randomized clinical study in humans assessing for a difference in healing and strength in a population of patients considered at high risk for postoperative failure of the repair. 3. STUDY OBJECTIVES Utilizing a randomized controlled trial, this study seeks to evaluate if there is a difference in post-operative healing, strength, and functional outcomes in patients older than 55 years with rotator cuff tears treated with and without the nanofiber scaffold.