Update on biologics in the treatment of rotator cuff disease.

Rotator cuff disease is the most common condition affecting the shoulder, causing significant pain and functional impairment in the adult population. Improvements in arthroscopic instrumentation and suture anchor technology have allowed the development of stronger constructs with multiple suture configurations, allowing repair of large and massive tears through minimally invasive means. However, although repair instrumentation and techniques have improved, healing rates have not. A high failure rate remains for large and massive rotator cuff tears. The next frontier in the management of rotator cuff disease is biologic augmentation to facilitate healing following repair. The biology of the patient and the tendon remains a notable factor in rotator cuff healing. Repair efforts are negatively affected by decreased vascularity with normal aging, increased collagen fragility, muscle atrophy, and fatty infiltration of the chronically torn tendon. Surgical techniques to enhance the biology of the repair site and improve mechanical stability should be used whenever possible. Recognizing the tear pattern and performing an anatomic, tension-free repair provides the best chance for success. Microfracture of the healing bed of the greater tuberosity and the use of vented suture anchors allow marrow contents from the humerus to bathe the repair site and facilitate healing. These surgical techniques can be used by the surgeon during any repair and may improve rotator cuff healing rates for large and massive tears. The use of medications in the postoperative period may facilitate tendon healing to bone. Matrix metalloproteinases (MMPs) play a role in the pathophysiology of rotator cuff disease. Doxycycline has anticatabolic effects and blocks the destructive action of MMPs. Bedi et al demonstrated that administration of oral doxycycline reduced MMP activity and enhanced healing at the enthesis following rotator cuff repair in a rat model. Doxycycline has the added benefit of protecting against infection with Propionibacterium acnes, which may inhibit healing of the rotator cuff. Chechik et al showed that atorvastatin had a beneficial effect on the repaired rotator cuff, increasing the biomechanical strength of the repair through a cyclooxygenase-2– dependent mechanism. Platelet-rich plasma (PRP) may be a safe adjuvant to rotator cuff repair; however, current studies have reported mixed results and have not shown improvement in healing rates or functional outcomes. Hoppe et al recently showed that platelet-released growth factors heighten tenocyte proliferation and promote synthesis of the extracellular matrix to enhance healing of rotator cuff tendon in a laboratory culture medium. More clinical studies are necessary to determine the efficacy of PRP injections for rotator cuff disease. Several papers presented at the 2013 Annual Meeting of the American Academy of Orthopaedic Surgeons demonstrated the use of biologics to facilitate healing in animal models. Angeline et al showed that low vitamin D levels negatively afMichael J. O’Brien, MD