title: Margin convergence anchorage to bone for reconstruction of the anterior attachment of the rotator cable.
abstract: OBJECTIVE
  The purpose of this study was to compare the biomechanical characteristics of a massive L-shaped retracted rotator cuff tear repaired with either soft-tissue side-to-side sutures or margin convergence anchorage to bone.
  
  
  METHODS
  Eight matched pairs of cadaveric shoulders were used. The supraspinatus and infraspinatus were secured in a clamp at 30° of glenohumeral abduction. The subscapularis was secured in a separate clamp, and a constant load was applied. A massive L-shaped rotator cuff tear of the supraspinatus and infraspinatus tendon was created. In all specimens the posterior aspect of the tear was repaired by a transosseous-equivalent technique. In 1 group we placed 2 margin convergence sutures between the supraspinatus and the rotator interval. In the comparison group, a suture anchor was inserted at the anterior attachment of the rotator cable. Margin convergence anchorage to bone was then performed between the supraspinatus and the rotator interval. Each specimen was tested with an Instron machine (Instron, Canton, MA) and a video digitizing system. A paired t test was used for statistical analysis.
  
  
  RESULTS
  Margin convergence anchorage to bone decreased gap formation at cycle 1, cycle 30, and yield load across the entire footprint (P < .05). In both constructs the anterior gap was greater than the posterior gap at cycle 1, cycle 30, and yield load (P < .05). Margin convergence anchorage to bone decreased hysteresis and increased stiffness during the first cycle and increased yield load (P < .05).
  
  
  CONCLUSIONS
  Using margin convergence anchorage to bone to restore the anterior attachment of the rotator cable decreased gap formation across the entire footprint and improved biomechanical properties for cycle 1 and yield load compared with soft-tissue margin convergence for massive rotator cuff repairs.
  
  
  CONCLUSIONS
  Repairing the anterior rotator cuff with margin convergence anchorage to bone may improve clinical outcomes of an L-shaped massive tear repair.
authors.affiliation: Orthopaedic Biomechanics Laboratory, VA Healthcare System and University of California, Irvine, California, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nguyen
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Quigley
authors.forename: Samuel E
authors.initials: SE
authors.lastname: Galle
authors.forename: Michelle H
authors.initials: MH
authors.lastname: McGarry
authors.forename: Bong Jae
authors.initials: BJ
authors.lastname: Jun
authors.forename: Ranjan
authors.initials: R
authors.lastname: Gupta
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Burkhart
authors.forename: Thay Q
authors.initials: TQ
authors.lastname: Lee
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017006:Rotator Cuff / Q000503:physiopathology / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D053441:Suture Anchors; D013536:Suture Techniques; D013708:Tendon Injuries / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome