Smolders L A, Knell S C, Park B, Pozzi A, Meij B P, Steffen F
Clinic for Small Animal Surgery, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
Clinic for Small Animal Surgery, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
Vet J. 2020 Feb;256:105435. doi: 10.1016/j.tvjl.2020.105435. Epub 2020 Feb 4.
Degenerative lumbosacral stenosis in dogs frequently involves L7-S1 foraminal stenosis and L7 nerve root compression. Surgical techniques to decompress the L7 nerve root include foraminotomy and intervertebral distraction. The objective of this study was to compare the effect of foraminotomy and intervertebral distraction on the total, cranial, and caudal compartmental volumes of the L7-S1 intervertebral neurovascular foramen (NF). CT images were obtained from eight canine lumbosacral (L5-CD1) specimens in the following sequential conditions: native spine (1), after dorsal laminectomy and partial discectomy of L7-S1 (2), after L7-S1 foraminotomy (3), after distraction with an interbody cage between L7 and S1 (4), after cage distraction stabilized with pedicle screw-rod fixation in neutral (5) and flexed position (6). The volume of the complete NF and its cranial and caudal subcompartments were calculated using the CT images and statistically compared between conditions. P < 0.05 was considered statistically significant. The volume of the complete NF was significantly increased after foraminotomy (mean ± standard deviation (146.8 ± 26.5%, P < 0.01) and after distraction (Condition 4, 121.0 ± 19.1%; Condition 5, 116.6 ± 29.3 %; Condition 6, 119.0 ± 21.8 %; P = 0.01) with no difference between the distraction conditions. Foraminotomy induced a significantly larger increase in total NF volume compared to distraction. Foraminotomy, but not distraction, induced a significant increase in volume of the cranial subcompartment (158.2 ± 33.2 %; P < 0.01). Foraminotomy is more effective in increasing the foraminal volume and especially the cranial subcompartment, which is where the L7 nerve root traverses the NF. Hence, foraminotomy may be more effective in decompressing the L7 nerve root.
犬退行性腰骶部狭窄常累及L7 - S1椎间孔狭窄和L7神经根受压。减压L7神经根的手术技术包括椎间孔切开术和椎间撑开术。本研究的目的是比较椎间孔切开术和椎间撑开术对L7 - S1椎间神经血管孔（NF）的总体积、头侧和尾侧腔室体积的影响。从8个犬腰骶部（L5 - CD1）标本在以下连续状态下获取CT图像：天然脊柱（1）、L7 - S1后路椎板切除术和部分椎间盘切除术后（2）、L7 - S1椎间孔切开术后（3）、L7和S1之间使用椎间融合器撑开后（4）、在中立位（5）和屈曲位（6）用椎弓根螺钉 - 棒固定稳定融合器撑开后。使用CT图像计算完整NF及其头侧和尾侧子腔室的体积，并在不同状态之间进行统计学比较。P < 0.05被认为具有统计学意义。椎间孔切开术后完整NF的体积显著增加（平均值±标准差（146.8 ± 26.5%，P < 0.01）），撑开术后也显著增加（状态4，121.0 ± 19.1%；状态5，116.6 ± 29.3%；状态6，119.0 ± 21.8%；P = 0.01），撑开各状态之间无差异。与撑开术相比，椎间孔切开术使NF总体积增加显著更大。椎间孔切开术，但不是撑开术，使头侧子腔室体积显著增加（158.2 ± 33.2%；P < 0.01）。椎间孔切开术在增加椎间孔体积尤其是L7神经根穿过NF的头侧子腔室方面更有效。因此，椎间孔切开术在减压L7神经根方面可能更有效。
