title: Effect of the Optimal Asymmetry on the Strength of Six-Strand Tendon Repair: An Ex Vivo Biomechanical Study.
abstract: OBJECTIVE
  To evaluate the mechanical properties of a 6-strand core suture repair with asymmetric purchase in the 2 tendon ends, in comparison with a repair with symmetric suture purchases.
  
  
  METHODS
  Under cyclic loading of the tendons, we recorded the fatigue strength (Forces × Cycles) of a 6-strand flexor tendon repair with different symmetry in the lengths of suture purchase in 60 porcine tendons. The symmetric repair was made with 3 groups of parallel Kessler repairs of equal suture purchase (10 mm from the cut end) in the 2 tendon stumps. The asymmetric core suture repairs were then made with a Kessler repair of equal suture purchase (10 mm from the cut end) in the 2 tendon stumps, and shifting 2 other Kessler repairs by 1, 2, 3, 4, or 5 mm, respectively, along the longitudinal axis of the tendon in relation to the first (symmetric) Kessler repair.
  
  
  RESULTS
  The core repairs with 2 mm or more asymmetry in suture purchases in 2 tendon ends showed significantly greater fatigue strength compared with those with symmetric suture placement. The core repairs with 3 mm or more asymmetry in suture purchases in 2 tendon ends showed significantly smaller gaps compared with those with symmetric suture placement.
  
  
  CONCLUSIONS
  The core repairs with 3 mm or more asymmetry in suture purchases in 2 tendon ends generated increased fatigue strength and reduced gap sizes compared with those with symmetric suture placement in an ex vivo porcine model.
  
  
  CONCLUSIONS
  An asymmetric core suture repair with 3 mm or more difference in purchase length may allow for earlier rehabilitation and reduce the risk of postoperative complications.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kozono
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. Electronic address: t-okada@ortho.med.kyushu-u.ac.jp.
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Okada
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Naohide
authors.initials: N
authors.lastname: Takeuchi
authors.affiliation: Department of Information and System Engineering, Faculty of Information Engineering, Fukuoka Institute of Technology, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimoto
authors.affiliation: Department of Biorobotics, Faculty of Engineering, Kyushu Sangyo University, Fukuoka, Japan.
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Higaki
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Nakashima
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D023421:Models, Animal; D013536:Suture Techniques; D013552:Swine; D013708:Tendon Injuries / Q000503:physiopathology / Q000601:surgery*; D013710:Tendons / Q000503:physiopathology / Q000601:surgery*
keywords: Six-strand core suture; cyclic loading; ex vivo; fatigue strength; flexor tendon repair