Treatment with a Bioscaffold to Improve the Healing of a Patellar Tendon Defect: Short Term Results in the Rabbit Model

Introduction: The anterior cruciate ligament (ACL) is the most frequently injured ligament in the knee, often requiring surgical reconstruction. Central third bone-patellar tendon-bone (BPTB) autografts are commonly used for ACL reconstructions. Despite many advantages of the BPTB graft, harvesting of the graft often results in donor site morbidity including patellar baja and patellofemoral pain. Furthermore, the resulting defect in the patellar tendon (PT) has been observed to remain for years. Functional tissue engineering approaches have shown the potential to promote healing within the defect. Recently, our research center has demonstrated that a bioscaffold, namely porcine small intestinal submucosa (SIS), enhanced healing of an injured medial collateral ligament with a gap injury in a rabbit model. Our current research question is whether SIS could also enhance healing of a central PT defect. Thus, the objective of this study was to investigate the effect of SIS on the histological appearance, tissue dimensions, structural properties of the healing central BPTB complex, and mechanical properties of the healing PT tissue up to 12 weeks after creation of a central third defect in a rabbit model. Since SIS is an inductive bioscaffold, the hypothesis was that SIS will promote the growth of new healing tissue within the defect, resulting in an increased cross-sectional area (CSA) and improved structural properties of the healing central BPTB complex.