Aghayev Kamran, Dhar Utpal Kanti, Tsai Chi-Tay, Ahmedov Merdin, Vrionis Frank D
Department of Neurosurgery, Esencan Hospital, Istanbul, Turkey.
Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, USA.
Spine Surg Relat Res. 2024 Feb 14;8(4):448-457. doi: 10.22603/ssrr.2023-0240. eCollection 2024 Jul 27.
S1-L5 transdiscal screw fixation is a direct stabilization technique used for surgical treatment of high-grade (III-IV) L5-S1 spondylolisthesis. It has not been used for nonspondylolisthetic cases or in combination with an interbody cage (IC). This study aimed to develop a novel, direct S1-L5 sacrolumbar interbody fusion (SLIF) technique, a combination of IC and sacrolumbar transdiscal screw.
SLIF was tested in cadaveric, clinical, and finite element analysis settings. Three cadaveric lumbar spines were used to test the SLIF procedure before clinical application. Eight patients underwent the SLIF procedure. Clinical outcomes were evaluated by visual analog score for leg and back pain, short form 36, Oswestry disability index, and neurological examination. CT scans of the lumbar spine were used to assess the hardware placement and subsequent fusion. Finite element analysis was performed on a healthy human CT-based L5-S1 model. Intact segment, unilateral facetectomy and discectomy, SLIF, and transforaminal lumbar interbody fusion (TLIF) procedures were compared in terms of the range of motion (ROM), von Mises stress on hardware, and shear-induced directional deformity. Additionally, the same set of tests were conducted in an osteoporotic model.
Excellent hardware placement was feasible in three cadavers and eight patients. Preoperative neurological deficits improved in all patients. Statistically significant improvements were obtained on all self-reported questionnaire scores. All patients developed solid, Bridwell grade I fusions. Biomechanical testing revealed similar outcomes for TLIF and SLIF regarding the ROM. However, the screw's von Mises stress and shear-induced directional deformity were low for SLIF of healthy and osteoporotic bone.
SLIF is a feasible, safe, and effective L5-S1 fusion option suitable for all clinical scenarios. It provides several biomechanical advantages, yielding excellent clinical outcomes.
S1-L5经椎间盘螺钉固定是一种直接稳定技术，用于手术治疗高级别（III-IV级）L5-S1椎体滑脱。它尚未用于非椎体滑脱病例或与椎间融合器（IC）联合使用。本研究旨在开发一种新型的直接S1-L5腰骶椎间融合（SLIF）技术，即IC与腰骶经椎间盘螺钉的联合应用。
在尸体、临床和有限元分析环境中对SLIF进行测试。在临床应用前，使用三个尸体腰椎来测试SLIF手术。八名患者接受了SLIF手术。通过腿部和背部疼痛视觉模拟评分、简短健康调查问卷36项、Oswestry功能障碍指数和神经学检查来评估临床结果。使用腰椎CT扫描评估内固定物位置及随后的融合情况。在基于健康人体CT的L5-S1模型上进行有限元分析。比较完整节段、单侧小关节切除和椎间盘切除、SLIF以及经椎间孔腰椎椎间融合（TLIF）手术在活动范围（ROM）、内固定物上的冯·米塞斯应力和剪切诱导的方向变形方面的情况。此外，在骨质疏松模型中进行了相同的一组测试。
在三个尸体和八名患者中，良好的内固定物放置是可行的。所有患者术前的神经功能缺损均有改善。所有自我报告的问卷评分均有统计学意义的改善。所有患者均形成了坚固的Bridwell I级融合。生物力学测试显示，TLIF和SLIF在ROM方面结果相似。然而，对于健康和骨质疏松骨的SLIF，螺钉的冯·米塞斯应力和剪切诱导的方向变形较低。
SLIF是一种适用于所有临床情况的可行、安全且有效的L5-S1融合选择。它具有多种生物力学优势，可产生优异的临床结果。
