Chin Kingsley R, Seale Jason A, Bruce Carl A, Yu Warren D, Anagnost Steven C, Kushwaha Vivek P, Sung Roger D, Gabriel Josue, Meyer Craig S, Crawford Neil R, Lore Vito
Less Exposure Surgery Specialists Institute (LESS Institute aka LESS Clinic), Fort Lauderdale, FL, USA.
Department of Orthopedics, Herbert Wertheim College of Medicine at Florida International University, Miami, FL, USA.
J Spine Surg. 2024 Sep 23;10(3):354-361. doi: 10.21037/jss-24-10. Epub 2024 Sep 4.
Achieving optimal immediate stability is crucial in lumbar fusion surgeries. Traditionally, four pedicle screws have been utilized to provide posterior stability at the L5-S1 level. However, the use of bilateral transfacet pedicle screws (TFPS) as an alternative construct has shown promising results in terms of biomechanical stability. This research paper investigates the biomechanical stability of TFPS with a lag design in comparison to equivalent-sized unilateral or bilateral fully threaded pedicle screw-rod (PSR) constructs at the L5-S1 disc level. The study assesses the immediate stability achieved by these constructs which have clinical implications in achieving lumbar segment fusion. We hypothesized that bilateral TFPS will yield immediate lumbar fixation that is comparable to unilateral or bilateral PSR constructs.
Cadaveric biomechanical testing was conducted to evaluate the stability of posterior fixation using bilateral TFPS (FacetFuse, LESSpine, Burlington, MA, USA), bilateral and unilateral PSR (PedFuse Return, LESSpine, Burlington, MA, USA) constructs measuring 5.0 mm × 40 mm. A comprehensive analysis of range of motion (ROM) and stability under various loading conditions was performed to a maximum of 7.5 Nm. The constructs were assessed for their ability to provide immediate stability at the L5-S1 disc level.
Fourteen specimens were analyzed with an average age of 53.14±10.99 years and comparable bone mineral density. TFPS demonstrated a reduced ROM that was notably lower than that of unilateral PSR in all loading modes and was comparable to bilateral PSR, especially in extension and axial rotation (AR). The unilateral and bilateral PSR groups differed notably in lateral bending (LB) and AR.
Bilateral TFPS demonstrated superior immediate stability than unilateral PSR and was an equivalent substitute to bilateral PSR constructs at the L5-S1 disc level. Further clinical investigations are necessary to validate these results and ascertain the long-term outcomes and advantages associated with the use of bilateral TFPS as an alternative construct. Our findings showed that bilateral TFPS could potentially reduce the number of required pedicle screws while achieving comparable stability in lumbar fusion procedures.
在腰椎融合手术中实现最佳即刻稳定性至关重要。传统上，在L5-S1节段使用四颗椎弓根螺钉来提供后方稳定性。然而，使用双侧经关节突椎弓根螺钉（TFPS）作为替代结构在生物力学稳定性方面已显示出有前景的结果。本研究论文探讨了带拉力设计的TFPS与同等尺寸的单侧或双侧全螺纹椎弓根螺钉-棒（PSR）结构在L5-S1椎间盘水平的生物力学稳定性。该研究评估了这些结构所实现的即刻稳定性，这对实现腰椎节段融合具有临床意义。我们假设双侧TFPS将产生与单侧或双侧PSR结构相当的即刻腰椎固定效果。
进行尸体生物力学测试，以评估使用双侧TFPS（FacetFuse，LESSpine，美国马萨诸塞州伯灵顿）、双侧和单侧PSR（PedFuse Return，LESSpine，美国马萨诸塞州伯灵顿）结构（尺寸为5.0毫米×40毫米）进行后方固定的稳定性。对各种加载条件下的运动范围（ROM）和稳定性进行了全面分析，最大加载至7.5牛米。评估这些结构在L5-S1椎间盘水平提供即刻稳定性的能力。
分析了14个标本，平均年龄为53.14±10.99岁，骨密度相当。TFPS在所有加载模式下均表现出ROM降低，明显低于单侧PSR，且与双侧PSR相当，尤其是在伸展和轴向旋转（AR）方面。单侧和双侧PSR组在侧方弯曲（LB）和AR方面有显著差异。
双侧TFPS在L5-S1椎间盘水平显示出比单侧PSR更好的即刻稳定性，并且是双侧PSR结构的等效替代物。需要进一步的临床研究来验证这些结果，并确定与使用双侧TFPS作为替代结构相关的长期结果和优势。我们的研究结果表明，双侧TFPS在腰椎融合手术中有可能减少所需椎弓根螺钉的数量，同时实现相当的稳定性。
