title: A knotless flexor tendon repair technique using a bidirectional barbed suture: an ex vivo comparison of three methods.
abstract: BACKGROUND
  Flexor tendon repairs using conventional suture require knots that enlarge the cross-sectional area at the repair site. This enlargement increases the force of finger flexion and jeopardizes the integrity of a nascent tendon repair during rehabilitation. The authors hypothesized that a knotless flexor tendon repair using bidirectional barbed suture has similar strength and with reduced cross-sectional area compared with traditional techniques.
  
  
  METHODS
  Sixty-six fresh porcine flexor digitorum profundus tendons were divided randomly into three groups. Tendons were transected and repaired with one of the following techniques: two-strand Kessler technique, four-strand Savage technique, or four-strand knotless technique. The cross-sectional area of each tendon was calculated at the repair site before and after repair. All tendons underwent mechanical testing to assess the 2-mm-gap formation force and ultimate strength.
  
  
  RESULTS
  The 2-mm-gap formation force and ultimate strength of the Savage and knotless technique groups were not significantly different; however, both were significantly greater than those of the Kessler repair group (p<0.05). The repair-site cross-sectional area of tendons repaired with the knotless technique was significantly smaller than that of tendons repaired with the Kessler or Savage technique (p<0.01). Tendons repaired with the knotless technique also had a significantly smaller change in repair-site cross-sectional area (p<0.01).
  
  
  CONCLUSIONS
  The authors demonstrate that knotless flexor tendon repair with barbed suture has equivalent strength and reduced repair-site cross-sectional area compared with traditional techniques. The smaller tendon profile may decrease gliding resistance, thus reducing the risk for postsurgical tendon rupture during rehabilitation.
authors.affiliation: Morgantown, W.Va.; Durham, N.C.; Philadelphia, Pa. From the Department of Surgery, Section of Plastic Surgery, West Virginia University School of Medicine, the Department of Orthopaedic Surgery, Duke University School of Medicine, and the Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania.
authors.forename: W Thomas
authors.initials: WT
authors.lastname: McClellan
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Schessler
authors.forename: David S
authors.initials: DS
authors.lastname: Ruch
authors.forename: L Scott
authors.initials: LS
authors.lastname: Levin
authors.forename: Richard D
authors.initials: RD
authors.lastname: Goldner
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D066298:In Vitro Techniques; D019651:Plastic Surgery Procedures / Q000379:methods*; D012680:Sensitivity and Specificity; D013536:Suture Techniques; D013537:Sutures; D013552:Swine; D013710:Tendons / Q000601:surgery*; D013718:Tensile Strength