title: The biomechanical role of scaffolds in augmented rotator cuff tendon repairs.
abstract: BACKGROUND
  Scaffolds continue to be developed and used for rotator cuff repair augmentation; however, the appropriate scaffold material properties and/or surgical application techniques for achieving optimal biomechanical performance remains unknown. The objectives of the study were to simulate a previously validated spring-network model for clinically relevant scenarios to predict: (1) the manner in which changes to components of the repair influence the biomechanical performance of the repair and (2) the percent load carried by the scaffold augmentation component.
  
  
  METHODS
  The models were parametrically varied to simulate clinically relevant scenarios, namely, changes in tendon quality, altered surgical technique(s), and different scaffold designs. The biomechanical performance of the repair constructs and the percent load carried by the scaffold component were evaluated for each of the simulated scenarios.
  
  
  RESULTS
  The model predicts that the biomechanical performance of a rotator cuff repair can be modestly increased by augmenting the repair with a scaffold that has tendon-like properties. However, engineering a scaffold with supraphysiologic stiffness may not translate into yet stiffer or stronger repairs. Importantly, the mechanical properties of a repair construct appear to be most influenced by the properties of the tendon-to-bone repair. The model suggests that in the clinical setting of a weak tendon-to-bone repair, scaffold augmentation may significantly off-load the repair and largely mitigate the poor construct properties.
  
  
  CONCLUSIONS
  The model suggests that future efforts in the field of rotator cuff repair augmentation may be directed toward strategies that strengthen the tendon-to-bone repair and/or toward engineering scaffolds with tendon-like mechanical properties.
authors: Department of Biomedical Engineering and Orthopedic Research Center, Cleveland Clinic, Cleveland, OH, USA.
authors: Amit
authors: A
authors: Aurora
authors: Jesse A
authors: JA
authors: McCarron
authors: Antonie J
authors: AJ
authors: van den Bogert
authors: Jorge E
authors: JE
authors: Gatica
authors: Joseph P
authors: JP
authors: Iannotti
authors: Kathleen A
authors: KA
authors: Derwin
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D006801:Humans; D008953:Models, Anatomic; D016059:Range of Motion, Articular / Q000502:physiology; D019651:Plastic Surgery Procedures / Q000379:methods*; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000601:surgery; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery*; D013718:Tensile Strength; D015626:Tissue Expansion / Q000379:methods*; D054457:Tissue Scaffolds