title: Mechanical and structural characteristics of the new BONE-LOK cortical-cancellous internal fixation device.
abstract: The purpose of this study was to evaluate the structural and mechanical characteristics of a new and unique titanium cortical-cancellous helical compression anchor with BONE-LOK (Triage Medical, Inc., Irvine, CA) technology for compressive internal fixation of fractures and osteotomies. This device provides fixation through the use of a distal helical anchor and a proximal retentive collar that are united by an axially movable pin (U.S. and international patents issued and pending). The helical compression anchor (2.7-mm diameter) was compared with 3.0-mm diameter titanium cancellous screws (Synthes, Paoli, PA) for pullout strength and compression in 7# and 12# synthetic rigid polyurethane foam (simulated bone matrix), and for 3-point bending stiffness. The following results (mean +/- standard deviation) were obtained: foam block pullout strength in 12# foam: 2.7-mm helical compression anchor 70 +/- 2.0 N and 3.0-mm titanium cancellous screws 37 +/- 11 N; in 7# foam: 2.7-mm helical compression anchor 33 +/- 3 N and 3.0-mm titanium cancellous screws 31 +/- 12 N. Three-point bending stiffness, 2.7-mm helical compression anchor 988 +/- 68 N/mm and 3.0-mm titanium cancellous screws 845 +/- 88 N/mm. Compression strength testing in 12# foam: 2.7-mm helical compression anchor 70.8 +/- 4.8 N and 3.0-mm titanium cancellous screws 23.0 +/- 3.1 N, in 7# foam: 2.7-mm helical compression anchor 42.6 +/- 3.2 N and 3.0-mm titanium cancellous screws 10.4 +/- 0.9 N. Results showed greater pullout strength, 3-point bending stiffness, and compression strength for the 2.7-mm helical compression anchor as compared with the 3.0-mm titanium cancellous screws in these testing models. This difference represents a distinct advantage in the new device that warrants further in vivo testing.
authors.affiliation: Aestheticare Podiatric Surgical Residency Program, San Juan Capistrano, California, USA.
authors.forename: Victor V
authors.initials: VV
authors.lastname: Cachia
authors.forename: Brad
authors.initials: B
authors.lastname: Culbert
authors.forename: Chris
authors.initials: C
authors.lastname: Warren
authors.forename: Richard
authors.initials: R
authors.lastname: Oka
authors.forename: Andrew
authors.initials: A
authors.lastname: Mahar
mesh_terms: D001863:Bone Screws / Q000592:standards*; D005529:Foot Bones / Q000601:surgery; D016268:Internal Fixators / Q000592:standards*; D019563:Mechanics; D008961:Models, Structural; D010027:Osteotomy / Q000295:instrumentation; D014025:Titanium
chemical_list: D014025:Titanium