title: Arthroscopic suture retrievers and shuttles: a biomechanical investigation of the force required for tendon penetration and defect size.
abstract: BACKGROUND
  To compare instruments designed for arthroscopic suture handling during arthroscopic rotator cuff repair, to assess the force needed to penetrate the tendon, and to evaluate the residual defect size.
  
  
  METHODS
  Twenty-one instruments were each tested ten times on thawed sheep infraspinatus tendons. The force needed to pierce the tendon with each instrument was measured using a custom setup. Bone wax plates were used to make the perforation marks visible and to quantify the lesions each instrument created.
  
  
  RESULTS
  The force to pierce a tendon had a range of 5.6-18.5 N/mm. Within the group of suture retrievers, the angled instruments required in average 85 % higher forces than straight instruments. The lesion area had a range of 2-7 mm(2). Suture retrievers produced significantly larger lesion sizes compared with suture shuttles.
  
  
  CONCLUSIONS
  For the identical task of passing a suture through a tendon, differences exist regarding the ease of tendon penetration and potential damage to the tendon for different tools. The design, function, and resulting lesion size may be relevant and important for surgical handling and to avoid excess structural damage to the tendon. These results suggest that choosing the most appropriate tools for arthroscopic suture stitching influences the ease of handling and final integrity of the tissue.
authors.affiliation: Orthopaedic Department, Balgrist Hospital, University of Zurich, Forchstrasse 340, CH-8008, Zurich, Switzerland. christopher.lenz@balgrist.ch.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Lenz
authors.affiliation: Orthopaedic Department, Balgrist Hospital, University of Zurich, Forchstrasse 340, CH-8008, Zurich, Switzerland. karl.wieser@balgrist.ch.
authors.forename: Karl
authors.initials: K
authors.lastname: Wieser
authors.affiliation: Orthopaedic Department, Private Hospital Maria Hilf, Klagenfurt, Austria. georg.lajtai@privatklinik-mariahilf.at.
authors.forename: Georg
authors.initials: G
authors.lastname: Lajtai
authors.affiliation: Orthopaedic Department, Balgrist Hospital, University of Zurich, Forchstrasse 340, CH-8008, Zurich, Switzerland. dominikcmeyer@balgrist.ch.
authors.forename: Dominik C
authors.initials: DC
authors.lastname: Meyer
mesh_terms: D000818:Animals; D001182:Arthroscopy / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena / Q000502:physiology; D012756:Sheep; D013525:Surgical Instruments / Q000592:standards; D013536:Suture Techniques / Q000295:instrumentation* / Q000592:standards; D013537:Sutures / Q000592:standards; D013710:Tendons / Q000502:physiology* / Q000601:surgery*