title: Shear lag sutures: Improved suture repair through the use of adhesives.
abstract: Suture materials and surgical knot tying techniques have improved dramatically since their first use over five millennia ago. However, the approach remains limited by the ability of the suture to transfer load to tissue at suture anchor points. Here, we predict that adhesive-coated sutures can improve mechanical load transfer beyond the range of performance of existing suture methods, thereby strengthening repairs and decreasing the risk of failure. The mechanical properties of suitable adhesives were identified using a shear lag model. Examination of the design space for an optimal adhesive demonstrated requirements for strong adhesion and low stiffness to maximize the strength of the adhesive-coated suture repair construct. To experimentally assess the model, we evaluated single strands of sutures coated with highly flexible cyanoacrylates (Loctite 4903 and 4902), cyanoacrylate (Loctite QuickTite Instant Adhesive Gel), rubber cement, rubber/gasket adhesive (1300 Scotch-Weld Neoprene High Performance Rubber & Gasket Adhesive), an albumin-glutaraldehyde adhesive (BioGlue), or poly(dopamine). As a clinically relevant proof-of-concept, cyanoacrylate-coated sutures were then used to perform a clinically relevant flexor digitorum tendon repair in cadaver tissue. The repair performed with adhesive-coated suture had significantly higher strength compared to the standard repair without adhesive. Notably, cyanoacrylate provides strong adhesion with high stiffness and brittle behavior, and is therefore not an ideal adhesive for enhancing suture repair. Nevertheless, the improvement in repair properties in a clinically relevant setting, even using a non-ideal adhesive, demonstrates the potential for the proposed approach to improve outcomes for treatments requiring suture fixation. Further study is necessary to develop a strongly adherent, compliant adhesive within the optimal design space described by the model.
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63110, United States; Department of Biomedical Engineering, Washington University, St Louis, MO 63130, United States.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Linderman
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63110, United States.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kormpakis
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63110, United States.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Gelberman
authors.affiliation: Engineering Education Center, Missouri University of Science and Technology, St Louis, MO 63131, United States.
authors.forename: Victor
authors.initials: V
authors.lastname: Birman
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States.
authors.forename: Ulrike G K
authors.initials: UGK
authors.lastname: Wegst
authors.affiliation: Department of Mechanical Engineering and Materials Science, Washington University, St Louis, MO 63130, United States. Electronic address: gening@seas.wustl.edu.
authors.forename: Guy M
authors.initials: GM
authors.lastname: Genin
authors.affiliation: Department of Orthopaedic Surgery, Washington University, St Louis, MO 63110, United States; Department of Biomedical Engineering, Washington University, St Louis, MO 63130, United States; Department of Mechanical Engineering and Materials Science, Washington University, St Louis, MO 63130, United States. Electronic address: thomopouloss@wustl.edu.
authors.forename: Stavros
authors.initials: S
authors.lastname: Thomopoulos
mesh_terms: D000268:Adhesiveness; D002102:Cadaver; D020099:Coated Materials, Biocompatible / Q000008:administration & dosage* / Q000737:chemistry; D003131:Combined Modality Therapy / Q000379:methods; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D033081:Shear Strength; D013314:Stress, Mechanical; D013536:Suture Techniques; D013537:Sutures; D013708:Tendon Injuries / Q000503:physiopathology / Q000628:therapy*; D013718:Tensile Strength; D014014:Tissue Adhesives / Q000008:administration & dosage*; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology
chemical_list: D020099:Coated Materials, Biocompatible; D014014:Tissue Adhesives
keywords: Adhesive; Biomechanics; Flexor tendon; Shear lag; Suture