title: A scoping review of biomechanical testing for proximal humerus fracture implants.
abstract: BACKGROUND
  Fixation failure is a relatively common sequela of surgical management of proximal humerus fractures (PHF). The purpose of this study is to understand the current state of the literature with regard to the biomechanical testing of proximal humerus fracture implants.
  
  
  METHODS
  A scoping review of the proximal humerus fracture literature was performed, and studies testing the mechanical properties of a PHF treatment were included in this review. Descriptive statistics were used to summarize the characteristics and methods of the included studies.
  
  
  RESULTS
  1,051 proximal humerus fracture studies were reviewed; 67 studies met our inclusion criteria. The most common specimen used was cadaver bone (87%), followed by sawbones (7%) and animal bones (4%). A two-part fracture pattern was tested most frequently (68%), followed by three-part (23%), and four-part (8%). Implants tested included locking plates (52%), intramedullary devices (25%), and non-locking plates (25%). Hemi-arthroplasty was tested in 5 studies (7%), with no studies using reverse total shoulder arthroplasty (RTSA) implants. Torque was the most common mode of force applied (51%), followed by axial loading (45%), and cantilever bending (34%). Substantial testing diversity was observed across all studies.
  
  
  CONCLUSIONS
  The biomechanical literature was found to be both diverse and heterogeneous. More complex fracture patterns and RTSA implants have not been adequately tested. These gaps in the current literature will need to be addressed to ensure that future biomechanical research is clinically relevant and capable of improving the outcomes of challenging proximal humerus fracture patterns.
authors.affiliation: Department of Orthopaedics, University of British Columbia, Centre for Hip Health & Mobility, Robert H.N. Ho Research Centre, 771 - 2635 Laurel Street, Vancouver, BC, V5Z 1 M9, Canada. dr.cruickshank@hotmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Cruickshank
authors.affiliation: Department of Orthopaedics, University of British Columbia, Centre for Hip Health & Mobility, Robert H.N. Ho Research Centre, 771 - 2635 Laurel Street, Vancouver, BC, V5Z 1 M9, Canada. kelly.lefaivre@vch.ca.
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Lefaivre
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Ontario, Canada. hermanjohal@gmail.com.
authors.forename: Herman
authors.initials: H
authors.lastname: Johal
authors.affiliation: School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada. macint@mcmaster.ca.
authors.forename: Norma J
authors.initials: NJ
authors.lastname: MacIntyre
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Ontario, Canada. sprags@mcmaster.ca.|Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. sprags@mcmaster.ca.
authors.forename: Sheila A
authors.initials: SA
authors.lastname: Sprague
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. scottta@mcmaster.ca.
authors.forename: Taryn
authors.initials: T
authors.lastname: Scott
authors.affiliation: Department of Orthopaedics, University of British Columbia, Centre for Hip Health & Mobility, Robert H.N. Ho Research Centre, 771 - 2635 Laurel Street, Vancouver, BC, V5Z 1 M9, Canada. pierre.guy@ubc.ca.
authors.forename: Pierre
authors.initials: P
authors.lastname: Guy
authors.affiliation: Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada. cripton@mech.ubc.ca.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cripton
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada. mckeem@smh.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: McKee
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Ontario, Canada. bhandam@mcmaster.ca.|Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. bhandam@mcmaster.ca.
authors.forename: Mohit
authors.initials: M
authors.lastname: Bhandari
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Ontario, Canada. gslobogean@umoa.umm.edu.|Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland, USA. gslobogean@umoa.umm.edu.
authors.forename: Gerard P
authors.initials: GP
authors.lastname: Slobogean
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D019544:Equipment Failure Analysis / Q000379:methods* / Q000592:standards; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D006801:Humans; D011475:Prosthesis Failure / Q000009:adverse effects; D012784:Shoulder Fractures / Q000175:diagnosis / Q000601:surgery*