title: Looped versus single-stranded flexor tendon repairs: a cadaveric mechanical study.
abstract: OBJECTIVE
  To compare the tensile properties of 4-strand modified Kessler flexor tendon repairs using a looped or single-stranded suture.
  
  
  METHODS
  We evaluated the mechanical properties of 4-strand Kessler zone II core suture repairs using either looped or single-stranded suture in human flexor digitorum profundus and flexor pollicis longus tendons. Forty repairs were performed on tendons from bilateral cadaveric hands: 20 matched tendons were divided into equal groups of 3-0 looped and 3-0 single-strand repairs and 20 additional matched tendons were divided into equal groups of 4-0 looped and 4-0 single-strand repairs. Repaired tendons were tested in uniaxial tension to failure to determine mechanical properties and failure modes. Data were analyzed to determine the effect of repair type (ie, looped vs single-stranded) for each suture caliber (ie, 3-0 and 4-0).
  
  
  RESULTS
  Single-strand repairs with 3-0 suture demonstrated a significantly greater maximum load to failure and a significantly higher force at 2-mm gap compared with repairs with looped 3-0 suture. All 8 looped repairs with 3-0 suture failed by suture pullout whereas 7 of 8 repairs with 3-0 single-stranded suture failed by suture breakage. The mechanical properties of looped versus single-stranded repairs with 4-0 caliber suture were not statistically different. Repairs with 4-0 caliber suture failed by suture breakage in 8 of 10 single-strand repairs and failed by suture pullout in 6 of 10 repairs with looped suture.
  
  
  CONCLUSIONS
  In a time-0 ex vivo human cadaveric core suture model, the mechanical properties of a 4-strand repair using 3-0 single-stranded suture were significantly better than the same 4-strand repair performed with looped suture.
  
  
  CONCLUSIONS
  Four-strand flexor tendon repairs with 3-0 suture are mechanically superior when performed with single-strand suture versus looped suture.
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO. Electronic address: kaddison@wustl.edu.
authors: Ryan P
authors: RP
authors: Calfee
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO.
authors: Sean
authors: S
authors: Boone
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO.
authors: Jeffrey G
authors: JG
authors: Stepan
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO.
authors: Daniel A
authors: DA
authors: Osei
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO.
authors: Stavros
authors: S
authors: Thomopoulos
authors: Department of Orthopedic Surgery, Washington University in St Louis School of Medicine, St Louis, MO.
authors: Martin I
authors: MI
authors: Boyer
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D005383:Finger Injuries / Q000601:surgery*; D006801:Humans; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery*; D013718:Tensile Strength
keywords: Flexor tendon; looped; repair; zone II