University Hospital Tübingen, Tübingen, Germany.
Orthop Surg. 2021 May;13(3):863-875. doi: 10.1111/os.12872. Epub 2021 Mar 24.
To evaluate the comparison between lordotic and non-lordotic transforaminal lumbar interbody fusion (TLIF) cages in degenerative lumbar spine surgery and analyze radiological as well as clinical outcome parameters in long-term follow up.
In a retrospective study design, we compared 37 patients with non-lordotic cage (NL-group) and 40 with a 5° lordotic cage (L-group) implanted mono- or bi-segmental in TLIF-technique from 2013 to 2016 and analyzed radiological parameters of pre- and postoperative (Lumbar lordosis (LL), segmental lordosis (SL), and pelvic tilt (PT), as well as clinical parameters in a follow-up physical examination using the Oswestry disability index (ODI), Roland-Morris Score (RMS), and visual analog scale (VAS).
Surgery was mainly performed in lower lumbar spine with a peak in L4/5 (mono-segmental) and L4 to S1 (bi-segmental), long-term follow-up was on average 4 years postoperative. According to the literature, we found significantly better results in radiological outcome in the L-group compared to the NL-group: LL increased 6° in L-group (51° preoperative to 57° postoperative) and decreased 1° in NL-group (50° to 49° (P < 0.001). Regarding SL, we found an increase of 5° in L-group (13° to 18°) and no difference in NL-group (15°)(P < 0.001). In PT, we found a clear benefit with a decrease of 2° in L-group (21° to 19°) and no difference in NL-group (P = 0.008). In direct group comparison, ODI in NL-group was 23% vs 28% in L-group (P = 0.25), RMS in NL-group was 8 points vs 9 points in L-group (P = 0.48), and VAS was in NL-group 2.7 vs 3.2 in L-group (P = 0.27) without significant differences. However, the clinical outcome in multivariate analysis indicated a significant multivariate influence across ODI and RMS of BMI (Wilks λ = 0.57, F [4, 44] = 3.61, P = 0.012) and preoperative SS (Wilks λ = 0.66, F [4, 44] = 2.54, P = 0.048). Age, gender, cage type and postoperative PT had no significant influence (P > 0.05). Intraoperatively, we saw three dura injuries that could be sutured without problems and had no consequences for the patient. In the follow-up, we did not find any material-related problems, such as broken screws or cage loosening, also no pseudarthrosis.
In conclusion, we think it's not cage design but other influenceable factors such as correct indication and adequate decompression that lead to surgical success and the minimal difference in the LL therefore seemed to be of subordinate importance.
评估在退行性腰椎疾病手术中，采用凸型与非凸型经椎间孔腰椎体间融合（TLIF）融合器的对比，并分析长期随访的影像学和临床结果参数。
在回顾性研究设计中，我们比较了 2013 年至 2016 年间采用 TLIF 技术植入单节段或双节段非凸型（NL 组）和 5°凸型（L 组）融合器的 37 例和 40 例患者，并分析了术前和术后的影像学参数（腰椎前凸角（LL）、节段前凸角（SL）和骨盆倾斜角（PT）），以及在随访体格检查中使用 Oswestry 残疾指数（ODI）、Roland-Morris 评分（RMS）和视觉模拟评分（VAS）的临床参数。
手术主要在较低的腰椎进行，L4/5 节段（单节段）和 L4 至 S1 节段（双节段）为高峰，平均术后随访时间为 4 年。根据文献，我们发现 L 组的影像学结果明显优于 NL 组：L 组的 LL 增加了 6°（术前 50°至术后 57°），而 NL 组减少了 1°（术前 50°至术后 49°（P<0.001）。在 SL 方面，L 组增加了 5°（术前 13°至术后 18°），而 NL 组没有差异（术前 15°）（P<0.001）。在 PT 方面，L 组明显获益，减少了 2°（术前 21°至术后 19°），而 NL 组没有差异（P=0.008）。在直接组间比较中，NL 组的 ODI 为 23%，L 组为 28%（P=0.25），NL 组的 RMS 为 8 分，L 组为 9 分（P=0.48），NL 组的 VAS 为 2.7，L 组为 3.2（P=0.27），无显著差异。然而，多变量分析表明，BMI（Wilks λ=0.57，F[4,44]=3.61，P=0.012）和术前 SS（Wilks λ=0.66，F[4,44]=2.54，P=0.048）的多变量影响显著。年龄、性别、融合器类型和术后 PT 无显著影响（P>0.05）。术中我们看到了 3 例硬脑膜损伤，可以缝合而没有问题，也没有对患者造成后果。在随访中，我们没有发现任何与材料相关的问题，如螺钉断裂或融合器松动，也没有假关节形成。
总之，我们认为导致手术成功的因素不是融合器的设计，而是其他可影响的因素，如正确的适应证和充分的减压，而 LL 的微小差异似乎显得次要。
