title: Are conventional reconstruction plates equivalent to precontoured locking plates for distal humerus fracture fixation? A biomechanics cadaver study.
abstract: BACKGROUND
  The optimal plate type and configuration for distal humerus fracture fixation has yet to be defined. Available biomechanical studies show conflicting results. No existing studies compare conventional reconstruction plates to newer precontoured distal humerus locking plates in both parallel and perpendicular configurations.
  
  
  METHODS
  Three groups of humerus specimens were compared via biomechanical testing in a cadaver model simulating metaphyseal comminution. Group 1 consisted of conventional reconstruction plates in a perpendicular configuration. Group 2 used precontoured locking plates in a perpendicular configuration. Group 3 used precontoured locking plates in a parallel configuration. Each group was tested for stiffness in anterior bending, posterior bending, axial compression, and torsion. The specimens then underwent cyclic loading followed by single load to failure in posterior bending.
  
  
  RESULTS
  There was no significant difference between the three groups for anterior bending, posterior bending, axial compression, or torsional stiffness. There was no significant difference in load to failure for any of the three groups. Screw loosening was significantly higher in Group 1 when compared to Groups 2 and 3 after cyclic loading.
  
  
  CONCLUSIONS
  In the early postoperative period, less expensive perpendicular conventional reconstruction plate constructs provide similar stiffness and load to failure properties to newer precontoured locking plate systems regardless of plate configuration.
authors.affiliation: Skagit Regional Clinics, 1400 E. Kincaid Street, Mount Vernon, WA 98274, USA. ryanckoonce@gmail.com
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Koonce
authors.forename: Todd H
authors.initials: TH
authors.lastname: Baldini
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Morgan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001860:Bone Plates; D002102:Cadaver; D019245:Compressive Strength; D055119:Elastic Modulus; D019544:Equipment Failure Analysis; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D050723:Fractures, Bone / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D006811:Humerus / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009038:Motion; D011474:Prosthesis Design; D013718:Tensile Strength