title: Biomechanical comparison of double grasping repair versus cross-locked cruciate flexor tendon repair.
abstract: OBJECTIVE
  This study was conducted to compare the in vitro biomechanical properties of tensile strength and gap resistance of a double grasping loop (DGL) flexor tendon repair with the established four-strand cross-locked cruciate (CLC) flexor tendon repair, both with an interlocking horizontal mattress (IHM) epitendinous suture. The hypothesis is that the DGL-IHM method which utilizes two looped core sutures, grasping and locking loops, and a single intralesional knot will have greater strength and increased gap resistance than the CLC-IHM method.
  
  
  METHODS
  Forty porcine tendons were evenly assigned to either the DGL-IHM or CLC-IHM group. The tendon repair strength, 2-mm gap force and load to failure, was measured under a constant rate of distraction. The stiffness of tendon repair was calculated and the method of repair failure was analyzed.
  
  
  RESULTS
  The CLC-IHM group exhibited a statistically significant greater resistance to gapping, a statistically significant higher load to 2-mm gapping (62.0 N), and load to failure (99.7 N) than the DGL-IHM group (37.1 N and 75.1 N, respectively). Ninety percent of CLC-IHM failures were a result of knot failure whereas 30 % of the DGL-IHM group exhibited knot failure.
  
  
  CONCLUSIONS
  This study demonstrates that the CLC-IHM flexor tendon repair method better resists gapping and has a greater tensile strength compared to the experimental DGL-IHM method. The authors believe that while the DGL-IHM provides double the number of sutures at the repair site per needle pass, this configuration does not adequately secure the loop suture to the tendon, resulting in a high percentage of suture pullout and inability to tolerate loads as high as those of the CLC-IHM group.
authors.affiliation: Department of Orthopaedics, UPMC Hamot, Erie, PA USA.
authors.forename: C Liam
authors.initials: CL
authors.lastname: Dwyer
authors.affiliation: Houston Methodist Orthopedics and Sports Medicine, Houston, TX USA.
authors.forename: D Dean
authors.initials: DD
authors.lastname: Dominy
authors.affiliation: Department of Orthopaedics, UPMC Hamot, Erie, PA USA.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Cooney
authors.affiliation: Penn State Erie, The Behrend College, Erie, PA USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Englund
authors.affiliation: University of California, San Francisco, CA USA.
authors.forename: Leonard
authors.initials: L
authors.lastname: Gordon
authors.affiliation: Department of Orthopaedics, UPMC Hamot, Erie, PA USA ; Hand, Microsurgery, and Reconstructive Orthopaedics LLP, 300 State Street, Suite 205, Erie, PA 16507 USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Lubahn
keywords: Biomechanical study; Flexor tendon repair