Pressure distributions inside intervertebral discs under unilateral pedicle screw fixation in a porcine spine model

Autor: Xuejun Zhang, Zhao Meng, Li-Jun Tian, Chen Wang, Dong Guo, Yan Zou
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Journal of Orthopaedic Surgery and Research
Journal of Orthopaedic Surgery and Research, Vol 13, Iss 1, Pp 1-7 (2018)
ISSN: 1749-799X
Popis: Background Little data are available regarding the effects of pedicle screws on the intervertebral disc stress for different spinal segments. The aim of this study was to analyze the intervertebral disc stress in response to the placement of pedicle screws. Methods T3–4, T11–12, T15–L1, L3–4, and L4–5 intervertebral disc segments from six porcine spine specimens were harvested. A compressive load of 200 N was applied both before and after the pedicle screw was implanted on the left side of each target segment; the resulting pressure was measured during vertical, 5° anterior flexion, 5° posterior extension, and 5° lateral bending. Results The posterior intradiscal pressures of the intervertebral disc were significantly lower in the fixed group than in the unfixed group for all segments during vertical, 5° anterior flexion, and 5° posterior extension. The left pressures of the intervertebral disc were significantly lower in the fixation group for all segments. During 5° lateral bending, the left intervertebral disc pressures were significantly lower in the fixation group. Lower mean pressures were observed in the fixed group. Conclusions Unilateral pedicle screws can effectively reduce the pressure of the fixed lateral intervertebral disc. Moreover, it can change the pressure distribution of the intervertebral disc and reduce the pressure of the entire intervertebral disc, especially the posterior side of the intervertebral disc.
Databáze: OpenAIRE