title: Proximal tendon-prosthesis junction for active tendon implants of the hand: a biomechanical comparison of 2 techniques.
abstract: OBJECTIVE
  To study the biomechanical characteristics (percent stretch, stiffness, and ultimate load) of 2 tendon-prosthesis techniques used to connect the proximal tendon stump to silicone active tendon implants used in reconstruction of flexor tendons.
  
  
  METHODS
  We evaluated percent stretch following cyclic loading and at failure, stiffness during load to failure, and ultimate load of 16 tendon-prosthesis junctions using cadaveric canine flexor digitorum profundus tendons to re-create 2 junction techniques: the tendon loop (TL) and the polyester weave (PW).
  
  
  RESULTS
  The TL junction showed greater percent stretch at a static load of 2 N, following 500 cycles of loading between 2 N and 50 N, and at peak load. The PW junction displayed greater stiffness from 50 to 150 N during load to failure. Both junctions failed at a mean ultimate load greater than 220 N.
  
  
  CONCLUSIONS
  The described proximal junction techniques for active tendon implants were strong enough to resist early active motion in the immediate postoperative period without significant elongation. The PW technique displayed greater stiffness and ultimate load compared with the TL.
  
  
  CONCLUSIONS
  Data on tendon-prosthesis characteristics of these 2 methods may aid the surgeon in choosing which junction technique to use, during surgical tensioning decisions, and in considering activity protocols after surgery. These data may also serve as a baseline for further investigations regarding active tendon implants.
authors.affiliation: Orthopaedic Research Laboratory, Departments of Orthopaedic Surgery & Biomedical Engineering, Virginia Commonwealth University, Richmond, VA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Thompson
authors.affiliation: Orthopaedic Research Laboratory, Departments of Orthopaedic Surgery & Biomedical Engineering, Virginia Commonwealth University, Richmond, VA.
authors.forename: John R
authors.initials: JR
authors.lastname: Owen
authors.affiliation: Orthopaedic Research Laboratory, Departments of Orthopaedic Surgery & Biomedical Engineering, Virginia Commonwealth University, Richmond, VA.
authors.forename: Charles L
authors.initials: CL
authors.lastname: McDowell
authors.affiliation: Orthopaedic Research Laboratory, Departments of Orthopaedic Surgery & Biomedical Engineering, Virginia Commonwealth University, Richmond, VA. Electronic address: jwayne@vcu.edu.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Wayne
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D004285:Dogs; D006230:Hand Injuries / Q000601:surgery*; D023421:Models, Animal; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000379:methods; D019651:Plastic Surgery Procedures / Q000379:methods*; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery*; D013710:Tendons / Q000503:physiopathology / Q000601:surgery*
keywords: Active tendon implant; Hunter technique; percent stretch; staged-tendon reconstruction; structural performance