title: Biomechanical comparison of techniques to reduce the bulk of lacerated flexor tendon ends within digital sheaths of the porcine forelimb.
abstract: OBJECTIVE
  Zone II flexor tendon repairs may create a bulging effect with increased bulk and resistance to tendon gliding. A biomechanical time 0 study was performed to assess 2 methods of tendon antibulking for work of flexion and strength characteristics.
  
  
  METHODS
  We placed 24 fresh-frozen porcine forelimb tendons in a custom jig. Deep flexor tendon was sectioned just distal to the intact A1 and A2 pulleys. Specimens were divided into 3 groups before repair: group 1, nonmodified tendon; group 2, 30 degrees bilateral notch excised from both tendon ends; and group 3, triangular longitudinal central wedge excised from both tendon ends. All repairs used a 4-strand modified Kessler core suture and running circumferential epitendinous suture. Work of flexion, 2-mm gap formation, and ultimate load to failure were tested.
  
  
  RESULTS
  Both antibulking techniques (groups 2 and 3) had significantly less work of flexion than group 1 (36.3 and 34.9 J vs 142.9 J, p < .001). There was no significant change in work of flexion between groups 2 and 3 (p > .05). There was no significant difference in terms of 2-mm gap formation among the 3 groups (p > .05). Groups 1 and 3 exhibited a significantly higher load to failure compared with group 2 (p < .05).
  
  
  CONCLUSIONS
  The antibulking repair techniques used in this study decrease the work of flexion with no significant change in force to 2-mm gap formation. Group 2, however, did have significantly lower load to failure. These techniques might be beneficial in zone II flexor tendon injury, in which the tight annular pulley system restricts tendon gliding. However, this is a time 0 study and the potential adverse effects of increase tendon manipulation and trauma were not analyzed, which might increase adhesions and scar during the healing phase of tendon repair.
authors.affiliation: Department of Orthopedic Surgery, Mount Sinai Medical Center, New York, NY 11210, USA. drvigler@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Vigler
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: R
authors.initials: R
authors.lastname: Palti
authors.forename: J C
authors.initials: JC
authors.lastname: Williams
authors.forename: A J
authors.initials: AJ
authors.lastname: Kaminsky
authors.forename: M A
authors.initials: MA
authors.lastname: Posner
authors.forename: M R
authors.initials: MR
authors.lastname: Hausman
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005552:Forelimb; D066298:In Vitro Techniques; D013552:Swine; D013708:Tendon Injuries / Q000503:physiopathology / Q000601:surgery*; D013710:Tendons / Q000503:physiopathology / Q000601:surgery*