L_4退变性滑脱症椎间盘真空征的临床意义

Clinical significances of vacuum phenomenon in patients with L_(4/5) degenerative spondylolisthesis

[目的]探讨退变性腰椎滑脱症椎间盘真空现象对腰椎骨盆矢状面形态和手术疗效的影响。[方法]回顾性分析2009年1月~2014年3月行TLIF手术治疗且有2年以上随访的125例Ⅰ~Ⅱ度退变性L_4椎滑脱症患者,其中男44例、女111例;年龄41~70岁(平均54.7岁)。根据在CT上是否伴有椎间盘真空现象将患者分为真空现象组和非真空现象组。于术前、术后和中期随访时,测量滑脱参数:滑脱率、滑脱角、椎间隙高度、局部后凸角;腰椎骨盆参数:骨盆入射角、骨盆倾斜角、骶骨倾斜角、腰椎前凸角和L_1椎体中心至骶骨垂线间距离。采用t检验比较两组间影像学的差异。[结果]本组伴椎间盘真空现象13例(10.4%)。真空现象组患者平均年龄显著高于非真空现象组[(60.7±13.6)岁∶(54.4±11.9)岁,P<0.05)]。术前真空现象组和非真空现象组滑脱率分别为(24.3±3.9)和(20.7±4.6)%,滑脱角分别为(2.7±2.1)°和(7.4±3.3)°,局部后凸角分别为(-1.4±2.3)°和(-8.2±4.7)°,椎间隙高度分别为(0.17±0.09)mm和(0.27±0.10)mm,两组比较差异均有统计学意义(P<0.05);术前真空现象组PT和LASD明显高于非后凸型滑脱组(P>0.05),而SS和LL明显小于非后凸型滑脱组(P<0.05),两组患者PI差异无统计学意义(P>0.05)。经TLIF手术后,两组患者术后及末次随访时各影像学指标较术前均明显改善。但至术后和末次随访时非真空现象组滑脱率、滑脱角和椎间隙高度改善均显著优于真空现象组(P<0.05);术后及末次随访时两组患者PI、PT、SS和LASD差异无统计学意义(P>0.05),但真空现象组LL显著小于非真空现象组。[结论]伴有椎间盘真空现象的L_4退变性滑脱患者椎间隙显著塌陷,是滑脱椎体复位不佳的预测指标。

[Objective] To investigate the influence of vacuum phenomenon in degenerative spondylolisthesis on the sagittal spinopelvic aligments and the surgical outcomes. [Methods] A retrospective study was conducted in 125 patients with L4/5 degenerative spendylolisthesis （Meyerding grade I or II） who underwent transforaminal lumbar interbody fusion （TLIF） between January 2009 and March 2014, including 14 males and 111 females, with an average age of 54.7 years ranged from 41 to 70 years. According to CT examination, the patients were divided into the vacuum phenomenon group and the non-vacuum phenomenon group. Sagittal spinopelvic alignments on radiographs were assessed and compared between the two groups The lo- ca/deformity parameters included slip angle （SA）, disc height （DH）, slip percentage （SP）, segmental kyphosis （SK）, additionally, the spinopelvic parameters consisted of pelvic incidence （PI）, pelvic tiff （PT）, sacral slope （SS）, lumbar lodorsis （LL）, L, axis S, distance （LASD） . [Results] Of the 125 patients, intradiscal vacuum phenomenon was noted in 13 （10.4%） patients. The average age of the vacuum phenomenon group were significant elder than that of the non- vacuum phenomenon group [ （60. 7±13.6） years vs （54. 4±11.9） years, P〈0.05]. The preoperative local deformity parameters, SP [ （24.3±3.9）% vs （20.7±4.6）%, P〈0.05], SA [（2.7±2.1） vs （7.4±3.3）, P〈0.05], SK [（-1.4±2.3） vs （- 8.2±4.7）, P〈0.05] and DH [ （0.17±0.09） vs （0.27±0.10）, P〈0.05], showed significantdifferencesbetweenthevacuum phenomenon group and the non-vacuum phenomenon groups. In terms of preoperative spinopelvic parameters, PT and LASD were significantly higher in the vacuum phenomenon group than those in the non-vacuum phenomenon group （P〈0.05）, conversely, LL and SS were significantly lower in the former than those in the latter （P〈0.05）, however, no significant difference in PI between the two groups was found. After TLIF procedure, the radiological parameters in both groups improved significantly, but the improvements of SA, SP, DH, SK and LL in the vacuum phenomenon group were significantly inferior to those of the non-vacuum phenomenon group （P〈0.05） . [Condusion] The vacuum phenomenon of L4/5 degenerative spondylolisthesis is usually accompanied by remarkable collapse of the intervertebral space, which could be used as a predictor of poor outcomes of reduction.