title: Biomechanical comparison of a single-row versus double-row suture anchor technique for rotator cuff repair.
abstract: BACKGROUND
  Reestablishment of the native footprint during rotator cuff repair has been suggested as an important criterion for optimizing healing potential and fixation strength.
  
  
  OBJECTIVE
  A double-row rotator cuff footprint repair will demonstrate superior biomechanical properties compared with a single-row repair.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  In 9 matched pairs of fresh-frozen cadaveric shoulders, the supraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique: 2 medial anchors with horizontal mattress sutures and 2 lateral anchors with simple sutures. The tendon from the contralateral shoulder was repaired using a single lateral row of 2 anchors with simple sutures. Each specimen underwent cyclic loading from 10 to 180 N for 200 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a video digitizing system; stiffness and failure load were determined from testing machine data.
  
  
  RESULTS
  Gap formation for the double-row repair was significantly smaller (P < .05) when compared with the single-row repair for the first cycle (1.67 +/- 0.75 mm vs 3.10 +/- 1.67 mm, respectively) and the last cycle (3.58 +/- 2.59 mm vs 7.64 +/- 3.74 mm, respectively). The initial strain over the footprint area for the double-row repair was nearly one third (P < .05) the strain of the single-row repair. Adding a medial row of anchors increased the stiffness of the repair by 46% and the ultimate failure load by 48% (P < .05).
  
  
  CONCLUSIONS
  Footprint reconstruction of the rotator cuff using a double-row repair improved initial strength and stiffness and decreased gap formation and strain over the footprint when compared with a single-row repair.
  
  
  CONCLUSIONS
  To achieve maximal initial fixation strength and minimal gap formation for rotator cuff repair, reconstructing the footprint attachment with 2 rows of suture anchors should be considered.
authors.affiliation: Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, Long Beach, CA 90822, USA. tqlee@med.va.gov
authors.forename: David H
authors.initials: DH
authors.lastname: Kim
authors.forename: Neal S
authors.initials: NS
authors.lastname: Elattrache
authors.forename: James E
authors.initials: JE
authors.lastname: Tibone
authors.forename: Bong-Jae
authors.initials: BJ
authors.lastname: Jun
authors.forename: Sergai N
authors.initials: SN
authors.lastname: DeLaMora
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Kvitne
authors.forename: Thay Q
authors.initials: TQ
authors.lastname: Lee
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D002140:California; D006801:Humans; D008875:Middle Aged; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D013536:Suture Techniques; D013710:Tendons / Q000601:surgery; D016896:Treatment Outcome