腰椎管狭窄单节段经椎间孔椎体间融合手术前后矢状位参数值的变化

Effects of single-segment transforaminal lumbar interbody fusion on global sagittal balance in patients with lumbar spinal stenosis

目的探讨腰椎管狭窄症(LSS)患者行单节段经椎间孔椎体间融合术(TLIF)前后脊柱-骨盆矢状位参数变化。方法随访2010年1月至2016年10月接受同一组医生治疗且资料完整的行单节段TLIF手术的LSS患者102例,61~85岁,平均(66.4±4.8)岁。测量术前及术后2年矢状位参数,定义脊柱-骨盆垂直轴(SVA)≥40 mm为矢状位失衡,将患者分为术前平衡组(n=65,术前SVA<40 mm)和术前失衡组(n=37,术前SVA≥40 mm),术前失衡组又分为恢复平衡组(n=23,术后SVA<40 mm)和未恢复平衡组(n=14,术后SVA≥40 mm)。采用视觉模拟评分法(VAS)、日本整形外科学会(JOA)腰痛评分和Oswestry功能障碍指数(ODI)评估术前及术后临床症状。结果 LSS患者术前矢状位失衡发生率为36.3%。与术前平衡组相比,术前失衡组术前腰椎前凸角(LL)和胸椎后凸角(TK)较小,骨盆入射角(PI)-LL和骨盆倾斜角(PT)较大,且术前VAS、JOA和ODI评分较差(P<0.05),而术前失衡组术后SVA、LL、TK和PI-LL的变化值高于术前平衡组(P<0.05)。术后2年随访,23例(62.2%)恢复矢状位平衡,14例(37.8%)未恢复平衡者术前SVA均>90 mm,且PI-LL均>20°。与恢复平衡组相比,未恢复平衡组术前SVA和PI-LL较大,且术前LL和TK较小(P<0.05),而术后VAS、JOA和ODI评分差异无统计学意义(P>0.05)。结论大多数术前矢状位失衡与患者保护性体位有关,单节段TLIF手术可有效改善矢状位失衡。研究亦未发现术后矢状位失衡与临床疗效的关联性,故术前矢状位失衡可能不适合单独作为LSS患者长节段矫形手术的依据。

Objective To explore the changes of anterior and posterior spinal-pelvic sagittal parameters in patients with lumbar spinal stenosis (LSS) who received single-segment transforaminal lumbar interbody fusion (TLIF). Methods The clinical data of 102 patients with LSS who underwent single-segment TLIF during Jan. 2010 and Oct. 2016 were retrospectively analyzed. The patients aged 61-85 years, average (66.4±4.8) years. The preoperative and 2-year postoperative sagittal parameters were determined, including lumbar lordosis (LL), thoracic kyphosis (TK), thoracolumbar junctional angle (TUA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA) and mismatch between pelvic incidence and lumbar lordosis (PI-LL). SVAM40 mm was defined as sagittal imbalance. Based on this, the patients were divided into the balance group (n = 65, SVA<40 mm) and imbalance group (n = 37, SVA≥40 mm) before operation. After operation, imbalance group were subdivided into the restoration group (n = 23,SVA<40 mm) and non-restoration group (n= 14, SVA≥40 mm). Visual Analog Scale (VAS) score, Japanese Orthopaedic Association (JOA) score and Oswestry Disability Index (ODI) were used to evaluate preoperative and postoperative clinical outcomes. Results The incidence of preoperative sagittal imbalance was 36.3%. Compared with the balance group, the imbalance group had smaller LL and TK, larger PI-LL and PT, and poorer VAS score, JOA score and ODI (all P<0.05). After operation, the imbalance group had greater changes in SVA, LL, TK and PI-LL than the balance group ( P<0.05). After 2 years of follow-up, the sagittal balance was restored in 23 patients (62.2%). The 14 patients who failed to restore the balance had preoperative SVA>90 mm, and PI-LL>20°. Compared with the restoration group, the non-restoration group had larger preoperative SVA and PI-LL, but smaller LL and TK (all P<0.05), while there were no differences in postoperative VAS, JOA and ODI between the two groups ( all P>0.05). Conclusion Most sagittal imbalance is related to patients' protective position, and single-segment TLIF can effectively improve sagittal imbalance. In addition, there is no correlation between postoperative sagittal imbalance and short-term clinical outcome. Therefore, preoperative sagittal imbalance alone may not be used as the indication for long-segment orthopedic surgery.