Basra Sushil, Bucklen Brandon, Muzumdar Aditya, Khalil Saif, Gudipally Manasa
Long Island Spine Specialists PC, 763 Larkfield Rd, 2nd Floor, Commack, NY 11725, USA.
Research and Development, Globus Medical, Inc., Valley Forge Business Center, 2560 General Armistead Ave., Audubon, PA 19403, USA.
Spine J. 2015 Feb 1;15(2):322-8. doi: 10.1016/j.spinee.2014.09.020. Epub 2014 Sep 26.
Lateral spacers (LSs) are the standard of care for a lateral lumbar interbody fusion. However, various types of fixation, such as bilateral pedicle screws (BPSs), unilateral pedicle screws (UPSs), bilateral facet screws (BFSs), and lateral plates (LPs) have been reported to increase the stability of LSs. The biomechanics of a novel lateral interbody implant, which is an interbody spacer with an integrated plate and two bone screws (lateral integrated plate-spacer [IPS-L]), has not been investigated yet.
To compare the biomechanical stability of IPS-L and LS with and without supplemental instrumentation.
Human lumbar cadaveric study evaluating the biomechanical stability of an IPS-L.
Each of the six (L2-L5) spines was sequentially tested in intact; IPS-L; IPS-L+UPS; IPS-L+BPS; IPS-L+BFS; LS+BFS; LS+UPS; LS+BPS; LS; and LS+LP, using a load-control protocol in which a ±8 Nm moment was applied, for three cycles each, in flexion-extension (FE), lateral bending (LB), and axial rotation (AR). Data results were obtained from the third cycle.
The IPS-L construct significantly reduced the range of motion (ROM) by 75% in FE, 70% in LB, and 57% in AR, compared with intact. Lateral integrated plate-spacer demonstrated similar biomechanical stability as LS+LP, and higher stability than the LS-alone construct, but the difference was not statistically significant.
The IPS-L evaluated in the present study demonstrated equivalent biomechanical stability compared with standard lateral interbody fusion constructs. The addition of BPSs to the IPS-L showed significant reduction in ROM in FE, and the addition of BFSs showed significant reduction in ROM in FE and AR, compared with the integrated plate-spacer alone construct. The IPS-L with supplemental fixation may be a viable option for lateral interbody fusion. Long-term clinical studies are further required to confirm these results.
外侧椎间融合器（LS）是腰椎外侧椎间融合术的标准治疗方法。然而，据报道，各种类型的固定方式，如双侧椎弓根螺钉（BPS）、单侧椎弓根螺钉（UPS）、双侧关节突螺钉（BFS）和外侧钢板（LP），可提高LS的稳定性。一种新型的外侧椎间植入物，即带有一体式钢板和两个骨螺钉的椎间融合器（外侧一体式钢板融合器[IPS-L]）的生物力学尚未得到研究。
比较有或无辅助器械时IPS-L和LS的生物力学稳定性。
评估IPS-L生物力学稳定性的人体腰椎尸体研究。
对六个（L2-L5）脊柱依次进行完整状态、IPS-L、IPS-L+UPS、IPS-L+BPS、IPS-L+BFS、LS+BFS、LS+UPS、LS+BPS、LS以及LS+LP状态下的测试，采用负载控制方案，在屈伸（FE）、侧方弯曲（LB）和轴向旋转（AR）时施加±8 Nm的力矩，每个动作重复三个周期。数据结果取自第三个周期。
与完整状态相比，IPS-L结构在FE时显著减少了75%的活动范围（ROM），在LB时减少了70%，在AR时减少了57%。外侧一体式钢板融合器表现出与LS+LP相似的生物力学稳定性，且比单独的LS结构具有更高的稳定性，但差异无统计学意义。
本研究中评估的IPS-L与标准的外侧椎间融合结构相比，表现出相当的生物力学稳定性。与单独的一体式钢板融合器结构相比，在IPS-L上添加BPS可使FE时的ROM显著降低，添加BFS可使FE和AR时的ROM显著降低。带有辅助固定的IPS-L可能是外侧椎间融合的一个可行选择。还需要进一步的长期临床研究来证实这些结果。
