The basic science behind biologic augmentation of tendon-bone healing: a scientific review.

Rotator cuff tears are common musculoskeletal injuries that often require surgical repair. Despite advances in surgical techniques, including progression from a single row of anchors to double-row constructs, recurrent tearing or failure to heal still complicates 10% to 94% of repairs. The surgical treatment of rotator cuff tears is aimed at providing the best mechanical environment for tendon healing. Despite appropriate surgical management and a normal healing response, the resultant tendon healing does not regenerate the tendon-bone architecture initially formed during prenatal development. Instead, a mechanically weaker, fibrovascular scar is formed, leading to suboptimal healing rates and/or higher retear rates. Biologic augmentation strategies aim to improve healing rates by introducing higher concentrations of growth factors and cytokines, mesenchymal stem cells, and enzymatic antagonists to the repair site in the hope of directing a more sophisticated healing response. Biologic augmentation and tissue engineering to improve tendon-to-bone healing remains promising but will require more study before its clinical application is realized.