title: The effect of suture preloading on the force to failure and gap formation after flexor tendon repair.
abstract: OBJECTIVE
  Gap formation is a common and severe complication after flexor tendon repair that can affect the outcome and prolong tendon healing. The purpose of this study was to investigate the effect that a pretensional force applied to the suture during tendon repair has on the repair strength and force that causes gap formation.
  
  
  METHODS
  We used a total of 48 flexor digitorum profundus tendons from 12 human cadaver hands. We employed a core tendon suture, using the modified Pennington technique, and a running suture for flexor tendon repair. Before tying the knots of the core suture, we preloaded the sutures in each tendon end 0, 5, 10, or 15 N for 10 seconds to compare the effect of loading magnitude on repaired tendon peak force to failure and force causing gap formation.
  
  
  RESULTS
  The force to form a gap of 2 mm in the 15-N preload group was significantly increased compared with the 0-N and 5-N preload groups. At the 3-mm gap formation, the force of all preload groups was significantly higher than the nonpreload group. The peak force with a preload of 10 N and 15 N was significantly higher than 0-N preload.
  
  
  CONCLUSIONS
  These findings suggest that pretensioning with 10 to 15 N at the suture-tendon interface before tying the knot has a beneficial effect on both the tendon gap formation and the peak force to failure.
  
  
  CONCLUSIONS
  When the surgeons perform tendon repair, pretensioning at the suture-tendon conjunction will increase the repair strength.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Vanhees
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.forename: Dirk R
authors.initials: DR
authors.lastname: Larson
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013536:Suture Techniques; D013708:Tendon Injuries / Q000601:surgery*; D013718:Tensile Strength