title: Maximum load to failure and tensile displacement of an all-suture glenoid anchor compared with a screw-in glenoid anchor.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the biomechanical behavior of an all-suture glenoid anchor in comparison with a more conventional screw-in glenoid anchor, with regard to maximum load to failure and tensile displacement.
  
  
  METHODS
  All mechanical testing was performed using an Instron ElectroPuls E1000 mechanical machine, with a 10 N pre-load and displacement rate of 10 mm/min. Force-displacement curves were generated, with calculation of maximum load, maximum displacement, displacement at 50 N and stiffness. Pretesting of handset Y-Knots in bone analog models revealed low force displacement below 60 N of force. Subsequently, three groups of anchors were tested for pull out strength in bovine bone and cadaver glenoid bone: a bioabsorbable screw-in anchor (Bio Mini-Revo, ConMed Linvatec), a handset all-suture anchor (Y-Knot, ConMed Linvatec) and a 60 N pre-tensioned all-suture anchor (Y-Knot). A total of 8 anchors from each group was tested in proximal tibia of bovine bone and human glenoids (age range 50-90).
  
  
  RESULTS
  In bovine bone, the Bio Mini-Revo displayed greater maximum load to failure (206 ± 77 N) than both the handset (140 ± 51 N; P = 0.01) and the pre-tensioned Y-Knot (135 ± 46 N; P = 0.001); no significant difference was seen between the three anchor groups in glenoid bone. Compared to the screw-in anchors, the handset all-suture anchor displayed inferior fixation, early displacement and greater laxity in the bovine bone and cadaveric bone (P < 0.05). Pre-tensioning the all-suture anchor to 60 N eliminated this behavior in all bone models.
  
  
  CONCLUSIONS
  Handset Y-Knots display low force anchor displacement, which is likely due to slippage in the pilot hole. Pre-tensioning the Y-Knot to 60 N eliminates this behavior.
  
  
  METHODS
  I.
authors.affiliation: Women's College, Toronto Western Hospital, University of Toronto Orthopaedic Sports Medicine, 76 Grenville St, Toronto, ON, M5S 1B1, Canada. drtimdwyer@yahoo.com.au.
authors.forename: Tim
authors.initials: T
authors.lastname: Dwyer
authors.affiliation: Musculoskeletal Research Laboratory, Division of Orthopaedic Surgery, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 25 Orde Street, Room 416, Toronto, ON, M5T 3H7, Canada.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Willett
authors.affiliation: University of Toronto, Toronto, ON, Canada.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Dold
authors.affiliation: Women's College Hospital, Toronto, ON, Canada.
authors.forename: Massimo
authors.initials: M
authors.lastname: Petrera
authors.affiliation: University of Toronto Orthopaedic Sports Medicine, Toronto, ON, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Wasserstein
authors.affiliation: Women's College Hospital, Toronto, ON, Canada.|St. Michael's Hospital, University of Toronto Orthopaedic Sports Medicine, Toronto, ON, Canada.
authors.forename: Danny B
authors.initials: DB
authors.lastname: Whelan
authors.affiliation: Women's College Hospital, Toronto, ON, Canada.|Mt. Sinai Hospital, University of Toronto Orthopaedic Sports Medicine, Toronto, ON, Canada.
authors.forename: John S
authors.initials: JS
authors.lastname: Theodoropoulos
mesh_terms: D000368:Aged; D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws; D002102:Cadaver; D002417:Cattle; D006801:Humans; D008875:Middle Aged; D012540:Scapula / Q000503:physiopathology* / Q000601:surgery*; D053441:Suture Anchors; D013536:Suture Techniques
keywords: All-suture anchor; Glenoid anchor; Y-Knot