Toop Nathaniel, Viljoen Stephanus, Baum Justin, Hatef Jeffrey, Maggio Dominic, Oosten James, Deistler Kyle, Gilkey Ty, Close Liesl, Farhadi H Francis, Grossbach Andrew J
1Department of Neurosurgery, The Ohio State University School of Medicine, Columbus; and.
2The Ohio State University School of Medicine, Columbus, Ohio.
J Neurosurg Spine. 2021 Dec 17;36(6):918-927. doi: 10.3171/2021.8.SPINE21687. Print 2022 Jun 1.
The aim of this study was to determine whether cage morphology influences clinical and radiographic outcomes following short-segment transforaminal lumbar interbody fusion (TLIF) procedures.
The authors retrospectively reviewed one- and two-level TLIFs at a single tertiary care center between August 2012 and November 2019 with a minimum 1-year radiographic and clinical follow-up. Two cohorts were compared based on interbody cage morphology: steerable "banana" cage or straight "bullet" cage. Patient-reported outcome measures (PROMs), radiographs, and complications were analyzed.
A total of 135 patients with 177 interbody levels were identified; 45 patients had 52 straight cages and 90 patients had 125 steerable cages. Segmental lordosis increased with steerable cages, while it decreased with straight cages (+3.8 ± 4.6 vs -1.9 ± 4.3, p < 0.001). Conversely, the mean segmental lordosis of adjacent lumbar levels decreased in the former group, while it increased in the latter group (-0.52 ± 1.9 vs +0.52 ± 2.1, p = 0.004). This reciprocal relationship results in global sagittal parameters, including pelvic incidence minus lumbar lordosis and lumbar distribution index, which did not change after surgery with either cage morphology. Multivariate analysis confirmed that steerable cage morphology, anterior cage positioning, and less preoperative index-level segmental lordosis were associated with greater improvement in index-level segmental lordosis. PROMs were improved after surgery with both cage types, and the degree of improvement did not differ between cohorts (p > 0.05). Perioperative and radiographic complications were similar between cohorts (p > 0.05). Overall reoperation rates, as well as reoperation rates for adjacent-segment disease within 2 years of surgery, were not significantly different between cohorts.
Steerable cages are more likely to lie within the anterior disc space, thus increasing index-level segmental lordosis, which is accompanied by a reciprocal change in segmental alignment at the adjacent lumbar levels. The converse relationship occurs for straight cages, with a kyphotic change at the index levels and reciprocal lordosis occurring at adjacent levels.
本研究旨在确定椎间融合器形态是否会影响短节段经椎间孔腰椎椎体间融合术（TLIF）后的临床和影像学结果。
作者回顾性分析了2012年8月至2019年11月在一家三级医疗中心进行的单节段和双节段TLIF手术，且有至少1年影像学和临床随访资料。根据椎间融合器形态将患者分为两组进行比较：可转向的“香蕉形”融合器或直的“子弹形”融合器。分析患者报告的结局指标（PROMs）、X线片和并发症情况。
共纳入135例患者的177个椎间节段；45例患者使用了52个直融合器，90例患者使用了125个可转向融合器。使用可转向融合器时节段前凸增加，而使用直融合器时节段前凸减小（分别为+3.8±4.6与-1.9±4.3，p<0.001）。相反，前一组相邻腰椎节段的平均节段前凸减小，而后一组增加（分别为-0.52±1.9与+0.52±2.1，p=0.004）。这种相互关系导致包括骨盆入射角减去腰椎前凸和腰椎分布指数在内的整体矢状面参数，在使用两种融合器形态手术后均未改变。多因素分析证实，可转向融合器形态、融合器前方位置以及术前指数节段节段前凸较小与指数节段节段前凸改善更大相关。两种融合器类型手术后PROMs均有改善，且两组改善程度无差异（p>0.05）两组围手术期和影像学并发症相似（p>0.05）。两组总体再手术率以及术后2年内相邻节段疾病再手术率无显著差异。
可转向融合器更有可能位于椎间盘前方间隙内，从而增加指数节段节段前凸，同时相邻腰椎节段的节段排列会发生相反变化。直融合器则相反，指数节段出现后凸改变，相邻节段出现相反的前凸。
