Posterior atlantoaxial fixation of osteoporotic odontoid fracture: biomechanical analysis of the Magerl versus harms techniques in a cadaver model.

Autor: Mike-Mayer A; The Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA., Lam K; Mount Sinai Medical Center, Max Biedermann Institute for Biomechanics, 4300 Alton Rd., Miami Beach, FL, USA., Morris RP; The Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA. Electronic address: rmorris@utmb.edu., Barghouthi AA; Mount Sinai Medical Center, Max Biedermann Institute for Biomechanics, 4300 Alton Rd., Miami Beach, FL, USA., Travascio F; Mount Sinai Medical Center, Max Biedermann Institute for Biomechanics, 4300 Alton Rd., Miami Beach, FL, USA; Department of Mechanical and Aerospace Engineering, University of Miami, 1251 Memorial Dr., Coral Gables, FL, USA; Department of Orthopaedics, University of Miami, 1611 NW 12th Ave #303, Miami, FL, USA., Latta LL; Mount Sinai Medical Center, Max Biedermann Institute for Biomechanics, 4300 Alton Rd., Miami Beach, FL, USA; Department of Orthopaedics, University of Miami, 1611 NW 12th Ave #303, Miami, FL, USA., Lindsey RW; The Department of Orthopedic Surgery and Rehabilitation, The University of Texas Medical Branch, 301 University Blvd., Galveston, TX, USA.
Jazyk: angličtina
Zdroj: The spine journal : official journal of the North American Spine Society [Spine J] 2024 Aug; Vol. 24 (8), pp. 1510-1516. Date of Electronic Publication: 2024 Apr 27.
DOI: 10.1016/j.spinee.2024.04.017
Abstrakt: Background Context: Odontoid fractures are among the most common cervical spine fractures in the elderly and are associated with increased morbidity and mortality. Clinical evidence suggests improved survival and quality of life after operative intervention compared to nonoperative treatment.
Purpose: This study seeks to examine the stability of an osteoporotic Type II odontoid fracture following posterior atlantoaxial fixation with either the Magerl transarticular fixation technique or the Harms C1 lateral mass screws C2 pedicle screw rod fixation.
Study Design: Biomechanical cadaveric study.
Methods: Eighteen cadaveric specimens extending from the cephalus to C7 were used in this study. Reflective marker arrays were attached to C1 and C2 and a single marker on the dens to measure movement of each during loading with C2-C3 and occiput-C1 being allowed to move freely. A biomechanical testing protocol imparted moments in flexion-extension, axial rotation, and lateral bending while a motion capture system recorded the motions of C1, C2, and the dens. The spines were instrumented with either the Harms fixation (n=9) or Magerl fixation (n=9) techniques, and a simulated Type II odontoid fracture was created. Motions of each instrumented spine were recorded for all moments, and then again after the instrumentation was removed to model the injured, noninstrumented state.
Results: Both Harms and Magerl posterior C1-C2 fixation allowed for C1, C2, and the dens to move as a relative unit. Without fixation the dens motion was coupled with C1. No significant differences were found in X, Y, Z translation motion of the dens, C1 or C2 during neutral zone motions between the Magerl and Harms fixation techniques. There were no significant differences found in Euler angle motion between the two techniques in either flexion-extension, axial rotation, or lateral bending motion.
Conclusions: Our findings suggest that both Harms and Magerl fixation can significantly reduce dens motion in Type II odontoid fractures in an osteoporotic cadaveric bone model.
Clinical Significance: Both Harms and Magerl posterior atlantoaxial fixation techniques allowed for C1, C2, and the dens to move as a relative unit following odontoid fracture, establishing more anatomic stability to the upper cervical spine.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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