title: Locking plate fixation provides superior fixation of humerus split type greater tuberosity fractures than tension bands and double row suture bridges.
abstract: BACKGROUND
  This paper aims to determine the strongest fixation method for split type greater tuberosity fractures of the proximal humerus by testing and comparing three fixation methods: a tension band with No. 2 wire suture, a double-row suture bridge with suture anchors, and a manually contoured calcaneal locking plate.
  
  
  METHODS
  Each method was tested on eight porcine humeri. A osteotomy of the greater tuberosity was performed 50° to the humeral shaft and then fixed according to one of three methods. The humeri were then placed in a testing apparatus and tension was applied along the supraspinatus tendon using a thermoelectric cooling clamp. The load required to produce 3mm and 5mm of displacement, as well as complete failure, was recorded using an axial load cell.
  
  
  RESULTS
  The average load required to produce 3mm and 5mm of displacement was 658N and 1112N for the locking plate, 199N and 247N for the double row, and 75N and 105N for the tension band. The difference between the three groups was significant (P<0.01). The average load to failure of the locking plate (810N) was significantly stronger than double row (456N) and tension band (279N) (P<0.05). The stiffness of the locking plate (404N/mm) was significantly greater than double row (71N/mm) and tension band (33N/mm) (P<0.01).
  
  
  CONCLUSIONS
  Locking plate fixation provides the strongest and stiffest biomechanical fixation for split type greater tuberosity fractures.
authors.affiliation: Université de Montréal, Montréal, Canada; Hôpital du Sacré-Cœur de Montréal, Montréal, Canada.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Gaudelli
authors.affiliation: Hôpital du Sacré-Cœur de Montréal Research Center, Montréal, Canada.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Ménard
authors.affiliation: Université de Montréal, Montréal, Canada; Hôpital du Sacré-Cœur de Montréal, Montréal, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mutch
authors.affiliation: Université de Montréal, Montréal, Canada; Hôpital du Sacré-Cœur de Montréal, Montréal, Canada.
authors.forename: G-Yves
authors.initials: GY
authors.lastname: Laflamme
authors.affiliation: Department of Mechanical Engineering, École de technologie supérieure, Montréal, Canada.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Petit
authors.affiliation: Université de Montréal, Montréal, Canada; Hôpital du Sacré-Cœur de Montréal, Montréal, Canada. Electronic address: dominique.rouleau@umontreal.ca.
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Rouleau
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D001864:Bone Wires; D004195:Disease Models, Animal; D019544:Equipment Failure Analysis; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D006811:Humerus / Q000601:surgery; D010027:Osteotomy / Q000379:methods; D017006:Rotator Cuff / Q000601:surgery; D012784:Shoulder Fractures / Q000601:surgery*; D013314:Stress, Mechanical; D053441:Suture Anchors; D013536:Suture Techniques; D013552:Swine
keywords: Biomechanics; Double-row suture-bridge fixation; Greater tuberosity fracture; Locking plate; Tension band