Christopher Melton

 It is estimated that 50 million sports injuries occur each year in the United States and the most common of those athletic injuries are ankle injuries¹.  The peroneal brevis and peroneal longus tendons are among the most frequently injured ankle tendons and are a source of chronic ankle pain².  Traditionally, peroneal tendon ruptures are surgically treated by direct repair or debridement and tubularization depending on severity of the injury³. Complete tendon healing requires a long period of time (1 to 2.5 years) post-injury, and the tissue may have less organized collagen fibrils that result in decreased mechanical strength, which increases the risk of re-injury⁴.  It has been proposed that the addition of tissue engineering with traditional surgical procedures may provide stronger and quicker repairs when compared to the traditional surgical repair alone^4-8.  Mesenchymal stem cells (MSCs) are among the most preferred source of stem cell in orthopedic tissue engineering because they can differentiate into several different tissue types⁵.  Several growth factors (growth differentiation factor 5, insulin-like growth factor, platelet-derived growth factor, basic fibroblastic growth factor, transforming growth factor beta, and vascular endothelial growth factor) are involved in activation and regulation of cellular responses during tendon repair and are potential additions to the MSCs to ensure proper differentiation⁶.  Sustained release of these growth factors inside a 3-D scaffold may provide an effective level of control when trying to influence cell phenotype, compared to simply adding growth factors to a culture medium⁶.  Suitable scaffolds must provide appropriate mechanical properties to provide support, biocompatibility of the substrate for cell attachment and proliferation, along with its biological signals^7-8.  Current animal models using tissue engineering to aid in tendon repair have provided convincing results in enhancing strength and speed of recovery^9-11.  These results provide convincing data that the addition of tissue engineering to traditional surgical procedures can be beneficial to human patients. This review sets out to evaluate the potential benefits and current limitations of the addition of tissue engineering to traditional peroneal tendon rupture surgical repair in humans.

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