title: The resistance of a four- and eight-strand suture technique to gap formation during tensile testing: an experimental study of repaired canine flexor tendons after 10 days of in vivo healing.
abstract: There is a high incidence of gap formation at the repair site following tendon repair. Our goal was to determine the resistance of a 4- and an 8-strand suture technique to gap formation during tensile testing. We hypothesized that the 8-strand repair would sustain higher force levels at the onset of 1- and 3-mm gaps than the 4- strand repair. Twenty-two canine flexor tendons were transected, repaired, and tested to failure after 10 days of in vivo healing. Tests were recorded using a 60-Hz video system that allowed frame-by-frame playback for assessment of gap formation. The 8-strand repairs sustained 80% higher force at a gap of 1 mm than the 4-strand repairs (average force, 70 vs 39 N), but the force sustained at a gap of 3 mm did not differ between groups (35 N for both groups). For both repair types, a 1-mm gap typically occurred near the point of ultimate (maximum) force while a 3-mm gap occurred after the ultimate force. We conclude that the 8-strand repair is significantly more resistant to initial gapping during ex vivo tensile testing than the 4-strand repair but that the two repairs are equally susceptible to rupture if a gap of 3 mm or greater forms.
authors.affiliation: Department of Orthopaedic Surgery, Barnes-Jewish Hospital at Washington University, St Louis, MO 63110, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Dinopoulos
authors.forename: M I
authors.initials: MI
authors.lastname: Boyer
authors.forename: M E
authors.initials: ME
authors.lastname: Burns
authors.forename: R H
authors.initials: RH
authors.lastname: Gelberman
authors.forename: M J
authors.initials: MJ
authors.lastname: Silva
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D017629:Gap Junctions / Q000502:physiology*; D008297:Male; D008422:Materials Testing; D018482:Muscle, Skeletal / Q000601:surgery; D011336:Probability; D013536:Suture Techniques; D013537:Sutures; D013710:Tendons / Q000601:surgery*; D013718:Tensile Strength; D014945:Wound Healing / Q000502:physiology