title: Flexor digitorum superficialis repair outside the A2 pulley after zone II laceration: gliding and bowstringing.
abstract: OBJECTIVE
  To evaluate the changes in maximum flexion angle, gliding coefficient, and bowstringing after a combined repair of both flexor tendons with the flexor digitorum superficialis (FDS) rerouted outside the A2 pulley in cadaveric hands.
  
  
  METHODS
  We performed 4 different repairs on cadaveric hands, with each repair tested on 9 unique digits. In total, 12 cadaveric hands and 36 digits were used. The thumb and little finger were removed from each hand and excluded from testing. Group 1 was sham surgery. Group 2 combined flexor digitorum profundus (FDP) and FDS laceration and repair with both slips of the FDS repaired inside the A2 pulley. Group 3 was FDP repair with one slip of the FDS repaired inside A2 and the other slip left unrepaired. Group 4 was FDP repair with both slips of the FDS rerouted and repaired outside the A2 pulley. Maximum flexion angle, gliding coefficient, and bowstringing were measured in simulated active digital motion for each group.
  
  
  RESULTS
  Rerouting and repairing the FDS outside the A2 pulley (group 4) significantly lowered gliding coefficient compared with repairs with both slips inside A2, with values similar to sham surgery. We observed no significant differences in maximum flexion angle among the 4 groups. Increased bowstringing was observed with both slips of the FDS repaired and rerouted outside the A2 pulley.
  
  
  CONCLUSIONS
  In this cadaveric model, repair of both slips of the FDS outside the A2 pulley improved the gliding coefficient relative to repair within the A2 pulley, which suggests decreased resistance to finger flexion. Repair of the FDS outside the A2 pulley led to a slight increase in bowstringing of the FDS tendon.
  
  
  CONCLUSIONS
  We describe a technique for managing combined laceration of the FDP and FDS tendons that improves gliding function and merits consideration.
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Geary
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY.
authors.forename: Christopher
authors.initials: C
authors.lastname: English
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY.
authors.forename: Zaneb
authors.initials: Z
authors.lastname: Yaseen
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY.
authors.forename: Spencer
authors.initials: S
authors.lastname: Stanbury
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY.
authors.forename: Hani
authors.initials: H
authors.lastname: Awad
authors.affiliation: Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY; Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY. Electronic address: John_Elfar@urmc.rochester.edu.
authors.forename: John C
authors.initials: JC
authors.lastname: Elfar
mesh_terms: D005383:Finger Injuries / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D022125:Lacerations / Q000601:surgery*; D019637:Orthopedic Procedures / Q000379:methods*; D020127:Recovery of Function; D013536:Suture Techniques; D013708:Tendon Injuries / Q000503:physiopathology / Q000601:surgery*; D013710:Tendons / Q000503:physiopathology / Q000601:surgery*
keywords: Flexor tendon laceration; flexor digitorum superficialis; flexor tendon repair; zone II