Anatomy and Deficiency of the Deltoid Muscle: A Review of Literature.

Journal and index pages often block iframe embedding. This reader keeps the evidence details in Orthonotes and leaves the source page one click away.

Abstract

Conflict of interest statement: The authors have no conflicts of interest to declare. 6. Acta Biomater. 2018 Apr 1;70:165-176. doi: 10.1016/j.actbio.2018.01.032. Epub 2018 Feb 8. Enhanced tendon-to-bone repair through adhesive films. Linderman SW(1), Golman M(2), Gardner TR(3), Birman V(4), Levine WN(3), Genin GM(5), Thomopoulos S(6). Author information: (1)Department of Orthopaedic Surgery, Washington University, St. Louis, MO 63110, United States; Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, United States. (2)Department of Orthopedic Surgery, Columbia University, New York, NY 10032, United States; Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States. (3)Department of Orthopedic Surgery, Columbia University, New York, NY 10032, United States. (4)Missouri S&T Global - St. Louis and Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, St. Louis, MO 63131, United States. (5)Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130, United States. Electronic address: gening@seas.wustl.edu. (6)Department of Orthopedic Surgery, Columbia University, New York, NY 10032, United States; Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States. Electronic address: sat2@cumc.columbia.edu. Tendon-to-bone surgical repairs have unacceptably high failure rates, possibly due to their inability to recreate the load transfer mechanisms of the native enthesis. Instead of distributing load across a wide attachment footprint area, surgical repairs concentrate shear stress on a small number of suture anchor points. This motivates development of technologies that distribute shear stresses away from suture anchors and across the enthesis footprint. Here, we present predictions and proof-of-concept experiments showing that mechanically-optimized adhesive films can mimic the natural load transfer mechanisms of the healthy attachment and increase the load tolerance of a repair. Mechanical optimization, based upon a shear lag model corroborated by a finite element analysis, revealed that adhesives with relatively high strength and low stiffness can, theoretically, strengthen tendon-to-bone repairs by over 10-fold. Lap shear testing using tendon and bone planks validated the mechanical models for a range of adhesive stiffnesses and strengths. Ex vivo human supraspinatus repairs of cadaveric tissues using multipartite adhesives showed substantial increase in strength. Results suggest that adhesive-enhanced repair can improve repair strength, and motivate a search for optimal adhesives. STATEMENT OF SIGNIFICANCE: Current surgical techniques for tendon-to-bone repair have unacceptably high failure rates, indicating that the initial repair strength is insufficient to prevent gapping or rupture. In the rotator cuff, repair techniques apply compression over the repair interface to achieve contact healing between tendon and bone, but transfer almost all force in shear across only a few points where sutures puncture the tendon. Therefore, we evaluated the ability of an adhesive film, implanted between tendon and bone, to enhance repair strength and minimize the likelihood of rupture. Mechanical models demonstrated that optimally designed adhesives would improve repair strength by over 10-fold. Experiments using idealized and clinically-relevant repairs validated these models. This work demonstrates an opportunity to dramatically improve tendon-to-bone repair strength using adhesive films with appropriate material properties. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. DOI: 10.1016/j.actbio.2018.01.032 PMCID: PMC5871607