title: Novel single-loop and double-loop knot stitch in comparison with the modified Mason-Allen stitch for rotator cuff repair.
abstract: OBJECTIVE
  In rotator cuff repair, strong and long-lasting suturing techniques that do not require additional implants are needed. This study examines the ultimate load to failure and the Young's modulus at the suture-tendon interface for a novel single-loop knot stitch and double-loop knot stitch. These values are compared to those of the modified Mason-Allen stitch.
  
  
  METHODS
  Twenty-four infraspinatus muscles with tendons were dissected from porcine shoulders (twelve Goettingen minipigs). The preparations were randomly allocated to three groups of eight samples. Load-to-failure testing of the single-loop knot stitch, the double-loop knot stitch and the mMAS were performed using a Zwick 1446 universal testing machine (Zwick-Roell AG, Ulm, Germany).
  
  
  RESULTS
  The highest ultimate load to failure for the three techniques occurred with the double-loop knot stitch with a median value of 382.2 N (range 291.8-454.2 N). These values were significantly higher than those of the single-loop knot stitch, which had a median value of 259.5 N (range 139.6-366.3 N) and the modified Mason-Allen stitch, which had a median value of 309.3 N (range 84.55-382.9 N). The values of the single-loop knot stitch and the modified Mason-Allen stitch did not differ significantly. Regarding the Young's modulus, no significant differences were found between the double-loop knot stitch with a median value of 496.02 N/mm² (range 400.4-572.6 N/mm²) and the modified Mason-Allen stitch with 498.5 N/mm² (range 375.5-749.2 N/mm²) with respect to the stiffness of the suture-tendon complex. The median value for the Young's modulus of the single-loop knot stitch of 392.1 N/mm² (range 285.7-510.6 N/mm²) was significantly lower than those of the double-loop knot stitch and modified Mason-Allen stitch.
  
  
  CONCLUSIONS
  This in vitro animal study demonstrated that both the single-loop knot stitch and the double-loop knot stitch have excellent ultimate load-to-failure properties when used for rotator cuff repair. The introduced single-loop knot stitch and double-loop knot stitch offer an alternative to other common used stitch techniques in rotator cuff repair.
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany. Stephan.Frosch@med.uni-goettingen.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Frosch
authors.affiliation: Department of Orthopedics, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Buchhorn
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Balcarek
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Schüttrumpf
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: August
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Klaus Michael
authors.initials: KM
authors.lastname: Stürmer
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Walde
authors.affiliation: Department of Trauma Surgery, Plastic and Reconstructive Surgery, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
authors.forename: Tim Alexander
authors.initials: TA
authors.lastname: Walde
mesh_terms: D000818:Animals; D001182:Arthroscopy / Q000379:methods*; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D013536:Suture Techniques / Q000295:instrumentation*; D013537:Sutures; D013552:Swine; D013556:Swine, Miniature
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