Is lateral stabilization enough in thoracolumbar burst fracture reconstruction? A biomechanical investigation

Ripul R Panchal; Erika A Matheis; Manasa Gudipally; Mir M Hussain; Kee D Kim; Brandon S Bucklen

doi:10.1016/j.spinee.2015.05.020

Is lateral stabilization enough in thoracolumbar burst fracture reconstruction? A biomechanical investigation

Spine J. 2015 Oct 1;15(10):2247-53. doi: 10.1016/j.spinee.2015.05.020. Epub 2015 May 22.

Authors

Ripul R Panchal¹, Erika A Matheis², Manasa Gudipally³, Mir M Hussain³, Kee D Kim¹, Brandon S Bucklen³

Affiliations

¹ Department of Neurological Surgery, University of California, Davis, 4860 Y St, Ste. 3740, Sacramento, CA 95817, USA.
² Muskuloskeletal Education and Research Center, A Division of Globus Medical Inc., 2560 General Armistead Ave., Audubon, PA 19403, USA. Electronic address: ematheis@globusmedical.com.
³ Muskuloskeletal Education and Research Center, A Division of Globus Medical Inc., 2560 General Armistead Ave., Audubon, PA 19403, USA.

PMID: 26008679
DOI: 10.1016/j.spinee.2015.05.020

Abstract

Background context: Traditional reconstruction for burst fractures involves columnar support with posterior fixation at one or two levels cephalad/caudad; however, some surgeons choose to only stabilize the vertebral column.

Purpose: The aim was to distinguish biomechanical differences in stability between a burst fracture stabilized through a lateral approach using corpectomy spacers of different end plate sizes with and without integrated screws and with and without posterior fixation.

Study design/setting: This was an in vitro biomechanical study assessing thoracolumbar burst fracture stabilization.

Methods: Six human spines (T11-L3) were tested on a six-degrees-of-freedom simulator enabling unconstrained range of motion (ROM) at ±6 N·m in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) after a simulated burst fracture at L1. Expandable corpectomy spacers with/without integrated screws (Fi/F; FORTIFY Integrated/FORTIFY; Globus Medical, Inc., Audubon, PA, USA) were tested with different end plate sizes (21×23 mm, 22×40-50 mm). Posterior instrumentation (PI) via bilateral pedicle screws and rods was used one level above and one level below the burst fracture. Lateral plate (LP) fixation was tested. Devices were tested in the following order: intact; Fi21×23; Fi21×23+PI; F21×23+PI+LP; F21×23+LP; F22×40-50+LP; F22×40-50+PI+LP; Fi22×40-50+PI; Fi22×40-50.

Results: In FE and AR, constructs without PI showed no significant difference (p<.05) in stability compared with intact. In LB, F22×40-50+LP showed a significant increase in stability relative to intact, but no other construct without PI reached significance. In FE and LB, circumferential constructs were significantly more stable than intact. In AR, no construct showed significant differences in motion when compared with the intact condition.

Conclusions: Constructs without posterior fixation were the least stable of all tested constructs. Circumferential fixation provided greater stability in FE and LB than lateral fixation and intact. Axial rotation showed no significant differences in any construct compared with the intact state.

Keywords: Biomechanics; Burst fracture; Range of motion; Stabilization; Thoracolumbar; Trauma.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Biomechanical Phenomena
Bone Plates / adverse effects
Female
Fracture Fixation / adverse effects*
Fracture Fixation / instrumentation
Fracture Fixation / methods
Humans
Male
Middle Aged
Pedicle Screws / adverse effects
Range of Motion, Articular
Spine / physiopathology
Spine / surgery*