title: Suture anchor fixation strength with or without augmentation in osteopenic and severely osteoporotic bones in rotator cuff repair: a biomechanical study on polyurethane foam model.
abstract: BACKGROUND
  The purpose of the present study was to compare the results of various types of anchor applications with or without augmentation in both osteopenic and severely osteoporotic bone models.
  
  
  METHODS
  Two different types of suture anchors were tested in severely osteoporotic (SOP) and osteopenic polyurethane (PU) foam blocks using an established protocol. An Instron machine applied static loading parallel to the axis of insertion until failure, and the mean anchor failure strengths were calculated. The mode of failure (anchor pullout, suture tear) was recorded. The anchors tested included the Corkscrew (CS) (Arthrex Inc., Naples, FL, USA) (without augmentation, polymethylmethacrylate (PMMA)-augmented, and bioabsorbable tricalcium phosphate (TCP) cement-augmented) and Corkscrew FT II (CS FT II) 5.5 mm (without augmentation as used routinely).
  
  
  RESULTS
  The mean failure loads for both SOP and osteopenic PU foam blocks, respectively, were as follows: CS, 16.2 and 212.4 N; CS with TCP, 75.2 and 396 N; CS with PMMA, 101.2 and 528.8 N; CS FT II, 13.8 and 339.8 N.
  
  
  CONCLUSIONS
  Augmentation of CS with TCP or PMMA would be essential to SOP bones. In the osteopenic bone model, although anchor fixation augmented with PMMA is the best fixation method, CS augmented with TCP cement or CS FT II without any need for augmentation may also be used as an alternative.
authors.affiliation: Department of Orthopaedics and Traumatology, Faculty of Medicine, Akdeniz University, Antalya 07985, Turkey. mserhan2005@hotmail.com.
authors.forename: Mehmet Serhan
authors.initials: MS
authors.lastname: Er
authors.forename: Levent
authors.initials: L
authors.lastname: Altinel
authors.forename: Mehmet
authors.initials: M
authors.lastname: Eroglu
authors.forename: Ozgur
authors.initials: O
authors.lastname: Verim
authors.forename: Teyfik
authors.initials: T
authors.lastname: Demir
authors.forename: Halil
authors.initials: H
authors.lastname: Atmaca
mesh_terms: D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D001851:Bone Diseases, Metabolic; D002130:Calcium Phosphates; D019544:Equipment Failure Analysis; D006801:Humans; D010024:Osteoporosis; D019904:Polymethyl Methacrylate / Q000627:therapeutic use*; D011140:Polyurethanes; D017006:Rotator Cuff / Q000601:surgery*; D000070636:Rotator Cuff Injuries; D012421:Rupture; D053441:Suture Anchors
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D011140:Polyurethanes; C028279:polyurethane foam; D019904:Polymethyl Methacrylate; C018392:tricalcium phosphate