title: Biomechanical comparison of 4 double-row suture-bridging rotator cuff repair techniques using different medial-row configurations.
abstract: OBJECTIVE
  Biomechanical comparison of different suture-bridge configurations of the medial row with respect to initial construct stability (time 0, porcine model).
  
  
  METHODS
  In 40 porcine fresh-frozen shoulders, the infraspinatus tendons were dissected from their insertions. All specimens were operated on by use of the suture-bridge technique, only differing in terms of the medial-row suture-grasping configuration, and randomized into 4 groups: (1) single-mattress (SM) technique, (2) double-mattress (DM) technique, (3) cross-stitch (CS) technique, and (4) double-pulley (DP) technique. Identical suture anchors were used for all specimens (medial: Bio-Corkscrew FT 5.5 [Arthrex, Naples, FL]; lateral: Bio-PushLock 3.5 [Arthrex]). All repairs were cyclically loaded from 10 to 60 N until 10 to 200 N (20-N stepwise increase after 50 cycles each) with a material testing machine. Forces at 3 and 5 mm of gap formation, mode of failure, and maximum load to failure were recorded.
  
  
  RESULTS
  The DM technique had the highest ultimate tensile strength (368.6 ± 99.5 N) compared with the DP (248.4 ± 122.7 N), SM (204.3 ± 90 N), and CS (184.9 ± 63.8 N) techniques (P = .004). The DM technique provided maximal force resistance until 3 and 5 mm of gap formation (90.0 ± 18.1 N and 128.0 ± 32.3 N, respectively) compared with the CS (72 ± 8.9 N and 108 ± 20.2 N, respectively), SM (66.0 ± 8.9 N and 90.0 ± 26.9 N, respectively), and DP (62.2 ± 6.2 N and 71 ± 13.2 N, respectively) techniques (P < .05 for each 3 and 5 mm of gap formation). The main failure mode was suture cutting through the tendon.
  
  
  CONCLUSIONS
  Comparing the 4 different suture-bridge techniques, we found that modified application of suture-bridge repair with double medial mattress stitches significantly enhanced biomechanical construct stability at time 0 in this porcine ex vivo model.
  
  
  CONCLUSIONS
  This technique increases initial stability and resistance to suture cutting through the rotator cuff tendon after arthroscopic suture-bridge repair.
authors.affiliation: Center for Musculoskeletal Surgery, Charité-Universitaetsmedizin Berlin, Berlin, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Pauly
authors.forename: Bettina
authors.initials: B
authors.lastname: Kieser
authors.forename: Alexander
authors.initials: A
authors.lastname: Schill
authors.forename: Christian
authors.initials: C
authors.lastname: Gerhardt
authors.forename: Markus
authors.initials: M
authors.lastname: Scheibel
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology*; D007839:Functional Laterality; D058430:Humeral Head / Q000033:anatomy & histology / Q000601:surgery; D008297:Male; D023421:Models, Animal; D017006:Rotator Cuff / Q000601:surgery*; D053441:Suture Anchors; D013537:Sutures; D013552:Swine; D013710:Tendons / Q000033:anatomy & histology / Q000601:surgery; D016474:Weight-Bearing