title: Primary fixation strength of rotator cuff repair techniques: a comparative study.
abstract: OBJECTIVE
  The goal of the study was to compare the primary fixation strength of transosseous suture, suture anchor, and hybrid repair techniques for rotator cuff repair.
  
  
  METHODS
  Animal model experiment.
  
  
  METHODS
  Thirty-two sheep shoulders were divided into 4 homogeneous groups, according to bone density and tendon dimensions. Infraspinatus tendons were transected from their insertions and reattached using 4 different techniques. Group 1 was repaired with a single Mason-Allen stitch and 2 transosseous tunnels for each end of the suture, knotted on the lateral cortex of proximal humerus; group 2 was repaired with double Mason-Allen stitches and 2 transosseous tunnels; group 3 was repaired with 2 Corkscrews (Arthrex, Germany); and group 4 was repaired with 2 Corkscrews combined with a single Mason-Allen transosseous suture. All specimens were tested for their fixation strengths with a material testing system.
  
  
  RESULTS
  The mode of failure in group 1 was mainly suture breakage. In groups 3 and 4, the tendons pulled out from the sutures. In group 2, sutures broke the bony bridge between the 2 tunnels. The mean load to failure value was 160.31 +/- 34.59 N in group 1, 199.36 +/- 11.73 N in group 2, 108.32 +/- 15.98 N in group 3, and 214.24 +/- 28.52 N in group 4. Anchor fixation was significantly weaker compared with other groups (P <.001). Combination of a transosseous suture and anchor fixation (group 4) was significantly stronger than the single transosseous suture (group 1) and double anchor techniques (group 3) (P <.001).
  
  
  CONCLUSIONS
  Hybrid technique was the strongest among the tested rotator cuff repair techniques. With the addition of one transosseous suture to two anchors, the strength of the repair could be doubled.
authors.affiliation: Department of Orthopaedics and Traumatology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey. msdemirhan@hotmail.com
authors.forename: Mehmet
authors.initials: M
authors.lastname: Demirhan
authors.forename: Ata Can
authors.initials: AC
authors.lastname: Atalar
authors.forename: Onder
authors.initials: O
authors.lastname: Kilicoglu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D020007:Implants, Experimental; D023421:Models, Animal; D019736:Prostheses and Implants; D017006:Rotator Cuff / Q000601:surgery*; D012756:Sheep; D013536:Suture Techniques / Q000295:instrumentation; D013718:Tensile Strength