Publisher DOI: 10.1007/s00586-013-3143-4
Title: Biomechanical advantage of C1 pedicle screws over C1 lateral mass screws : a cadaveric study
Language: English
Authors: Fensky, Florian 
Kueny, Rebecca A. 
Sellenschloh, Kay 
Püschel, Klaus 
Morlock, Michael M. 
Rueger, Johannes M. 
Lehmann, Wolfgang 
Huber, Gerd 
Hansen-Algenstaedt, Nils 
Keywords: Atlas; Biomechanical fixation strength; Lateral mass screw; Pedicle screw; Stiffness
Issue Date: 31-Dec-2013
Publisher: Springer
Source: European Spine Journal 23 (4): 724-731 (2014)
Abstract (english): 
Purpose: The established technique for posterior C1 screw placement is via the lateral mass. Use of C1 monocortical pedicle screws is an emerging technique which utilizes the bone of the posterior arch while avoiding the paravertebral venous plexus and the C2 nerve root. This study compared the relative biomechanical fixation strengths of C1 pedicle screws with C1 lateral mass screws. Methods: Nine human C1 vertebrae were instrumented with one lateral mass screw and one pedicle screw. The specimens were subjected to sinusoidal, cyclic (0.5 Hz) fatigue loading. Peak compressive and tensile forces started from ±25 N and constantly increased by 0.05 N every cycle. Testing was stopped at 5 mm displacement. Cycles to failure, displacement, and initial and end stiffness were measured. Finally, CT scans were taken and the removal torque measured. Results: The pedicle screw technique consistently and significantly outperformed the lateral mass technique in cycles to failure (1,083 ± 166 vs. 689 ± 240 cycles), initial stiffness (24.6 ± 3.9 vs. 19.9 ± 3.2 N/mm), end stiffness (16.6 ± 2.7 vs. 11.6 ± 3.6 N/mm) and removal torque (0.70 ± 0.78 vs. 0.13 ± 0.09 N m). Only 33 % of pedicle screws were loose after testing compared to 100 % of lateral mass screws. Conclusions: C1 pedicle screws were able to withstand higher toggle forces than lateral mass screws while maintaining a higher stiffness throughout and after testing. From a biomechanical point of view, the clinical use of pedicle screws in C1 is a promising alternative to lateral mass screws. © 2013 Springer-Verlag.
ISSN: 1432-0932
Journal: European spine journal 
Institute: Biomechanik M-3 
Document Type: Article
Project: Marie Curie ITN project SpineFX 
Funded by: Freie und Hansestadt Hamburg (FHH) 
More Funding information: Funding from the State of Hamburg and the Marie Curie ITN project SpineFX is kindly acknowledged.
Appears in Collections:Publications without fulltext

Show full item record

Page view(s)

Last Week
Last month
checked on May 28, 2023


Last Week
Last month
checked on Jun 29, 2022

PubMed Central

Last Week
Last month
checked on May 29, 2023

Google ScholarTM


Add Files to Item

Note about this record

Cite this record


Items in TORE are protected by copyright, with all rights reserved, unless otherwise indicated.