The C2 isthmus screw provided sufficient biomechanical stability in the setting of atlantoaxial dislocation-a finite element study-Reference-Cited by-同舟云学术

The C2 isthmus screw provided sufficient biomechanical stability in the setting of atlantoaxial dislocation-a finite element study

Published:2024-05-29 Issue:1 Volume:25 Page:
ISSN:1471-2474
Container-title:BMC Musculoskeletal Disorders
language:en
Short-container-title:BMC Musculoskelet Disord

Author:

Lu Minming,Wang Zhenqiang,Yuan Bo,Tang Yifan,Gu Changjiang,Zhou Shengyuan,Chen Xiongsheng

Abstract

Abstract Background The emerging of the C2 isthmus screw fixation technique is gaining popularity in the setting of atlantoaxial dislocation or other conditions requiring fixation of C2. However, the biomechanical stability of this fixation is poorly understood. Purpose To compare and elucidate the biomechanical stability of C2 pedicle screw (C2PS), C2 isthmus screw (C2IS) and C2 short isthmus screw (C2SIS) fixation techniques in atlantoaxial dislocation (AAD). Method A three-dimensional finite element model (FEM) from occiput to C3 was established and validated from a healthy male volunteer. Three FEMs, C1 pedicle screw (PS)-C2PS, C1PS-C2IS, C1PS-C2SIS were also constructed. The range of motion (ROM) and the maximum von Mises stress under flexion, extension, lateral bending and axial rotation loading were analyzed and compared. The pullout strength of the three fixations for C2 was also evaluated. Result C1PS-C2IS model showed the greatest decrease in ROM with flexion, extension, lateral bending and axial rotation. C1PS-C2PS model showed the least ROM reduction under all loading conditions than both C2IS and C2SIS. The C1PS-C2PS model had the largest von Mises stress on the screw under all directions followed by C1PS-C2SIS, and lastly the C1PS-C2IS. Under axial rotation and lateral bending loading, the three models showed the maximum and minimum von Mises stress on the screw respectively. The stress of the three models was mainly located in the connection of the screw and rod. Overall, the maximum screw pullout strength for C2PS, C2IS and C2SIS were 729.41N, 816.62N, 640.54N respectively. Conclusion In patients with atlantoaxial dislocations, the C2IS fixation provided comparable stability, with no significant stress concentration. Furthermore, the C2IS had sufficient pullout strength when compared with C2PS and C2SIS. C2 isthmus screw fixation may be a biomechanically favourable option in cases with AAD. However, future clinical trials are necessary for the evaluation of the clinical outcomes of this technique.

Publisher

Springer Science and Business Media LLC

Link

https://link.springer.com/content/pdf/10.1186/s12891-024-07470-6.pdf

Reference34 articles.

1. Cohen W.I. Current dilemmas in Down syndrome clinical care: celiac disease, thyroid disorders, and atlanto-axial instability. Am J Med Genet C Semin Med Genet. 2006;142c(3):p. 141-8. https://doi.org/10.1002/ajmg.c.30102.

2. Harms J, Melcher R.P. Melcher, Posterior C1-C2 fusion with polyaxial screw and rod fixation. Spine (Phila Pa 1976). 2001;26(22):p. 2467-71. https://doi.org/10.1097/00007632-200111150-00014.

3. Goel A, Laheri V. Plate and screw fixation for atlanto-axial subluxation. Acta Neurochir (Wien). 1994;129(1–2):p. 47-53. https://doi.org/10.1007/bf01400872.

4. Goel A, Desai K.I, Muzumdar D.P. Atlantoaxial fixation using plate and screw method: a report of 160 treated patients. Neurosurgery. 2002;51(6):p. 1351-6 discussion 1356–7.

5. Aryan HE, Newman CB, Nottmeier EW, Acosta FL Jr, Wang VY, Ames CP. Stabilization of the atlantoaxial complex via C-1 lateral mass and C-2 pedicle screw fixation in a multicenter clinical experience in 102 patients: modification of the Harms and Goel techniques. J Neurosurg Spine. 2008;8(3):222–9. https://doi.org/10.3171/spi/2008/8/3/222.