Biologic approaches to enhance rotator cuff healing after injury

Despite the advances in surgical procedures to repair the rotator cuff, there is a high incidence of failure. Biologic approaches, such as growth factor delivery and stem cell and gene therapy, are potential targets for optimization to improve the outcome of rotator cuff therapies and reduce rates of reinjury. This article outlines the current evidence for growth factor and stem cell therapy in tendon healing and the augmentation of rotator cuff repair.Literature on the PubMed-National Center for Biotechnology Information database was searched using the keywords growth factor, factor, gene therapy, stem cell, mesenchymal, or bone marrow in combination with rotator cuff, supraspinatus, or infraspinatus. Articles that studied growth factors or stem cells alone in rotator cuff repair were selected. Only 3 records showed use of stem cells in rotator cuff repair; thus, we expanded our search to include selected studies on stem cells and Achilles or patellar tendon repairs. Bibliographies and proceedings of meetings were searched to include additional applicable studies. We also included hitherto unpublished data by our group on the use of stem cell transplantation for rotator cuff therapy.More than 70 articles are summarized, with focus on recent original research papers and significant reviews that summarized earlier records.Use of growth factors, stem cell therapy, and other tissue-engineering means serve to augment classical surgical rotator cuff repair procedures. The combination of stem cells and growth factors resulted in enhanced repair that emulated uninjured tissue, but the literature search reflected paucity of research in this field. Preclinical evidence from gene therapy and stem cell studies can be used as a start to move therapy from the experimental phase to clinical translation in patients.