title: Flexor Tendon Repair With Looped Suture: 1 Versus 2 Knots.
abstract: OBJECTIVE
  To assess the strength of flexor tendon repair with looped suture. We hypothesized that, after passing the intact looped suture in the desired repair configuration, splitting the loop and tying 2 independent knots would increase the strength of flexor tendon repair.
  
  
  METHODS
  Thirty-two flexor tendons were harvested and were sharply transected in zone II. The tendons were repaired with a 4-strand core suture repair using 3-0 looped nonabsorbable nylon suture. The harvested tendons were randomly assigned and repaired with either a 1- or a 2-knot construct. The repaired flexor tendons were fixed in a servohydraulic material testing system and were loaded to failure either with uniaxial tension or cyclically.
  
  
  RESULTS
  The average force at failure was 43 N for the 1-knot repair and 28 N for the 2-knot repair. The mode of failure of 15 of the flexor tendon repairs that were cyclically loaded to failure was suture pull-out. The average number of cycles and force in cyclic testing that caused failure of flexor tendon repairs was 134 cycles and 31 N for tendons repaired with looped 3-0 suture tied with 1 knot and 94 cycles and 33 N for tendons repaired with looped 3-0 suture tied with 2 knots.
  
  
  CONCLUSIONS
  Our hypothesis was disproved by the results of this study.
  
  
  CONCLUSIONS
  This study suggests that, when using looped suture, tying 2 independent knots instead of tying a single knot does not increase the strength of the flexor tendon repair.
authors.affiliation: Department of Orthopaedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI. Electronic address: joseph_gil@brown.edu.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Gil
authors.affiliation: Department of Orthopaedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI.
authors.forename: Christian
authors.initials: C
authors.lastname: Skjong
authors.affiliation: Department of Orthopaedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Katarincic
authors.affiliation: Department of Orthopaedic Surgery, Warren Alpert School of Medicine, Brown University, Providence, RI.
authors.forename: Christopher
authors.initials: C
authors.lastname: Got
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008422:Materials Testing; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery; D013710:Tendons / Q000601:surgery*; D013718:Tensile Strength
keywords: Flexor tendon repair; core suture; flexor tendon laceration; looped suture; repair rupture