title: Axial pull-out strength of 3.5 cortical and 4.0 cancellous bone screws placed in canine proximal tibias using manual and power tapping.
abstract: An in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18-33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pull-out strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8+/-56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.
authors.affiliation: The Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi 39762, USA. demko@cvm.msstate.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Demko
authors.forename: M E
authors.initials: ME
authors.lastname: Soniat
authors.forename: S
authors.initials: S
authors.lastname: Elder
authors.forename: R
authors.initials: R
authors.lastname: McLaughlin
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D001863:Bone Screws / Q000662:veterinary*; D002102:Cadaver; D004285:Dogs / Q000601:surgery*; D016268:Internal Fixators; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D011897:Random Allocation; D013718:Tensile Strength; D013977:Tibia / Q000601:surgery*