Matsumoto Tomiya, Okuda Shinya, Maeno Takafumi, Yamashita Tomoya, Yamasaki Ryoji, Sugiura Tsuyoshi, Iwasaki Motoki
Department of Orthopaedic Surgery, Osaka Rosai Hospital, Sakai, Japan
J Neurosurg Spine. 2017 Apr;26(4):435-440. doi: 10.3171/2016.9.SPINE16232. Epub 2017 Jan 6.
The importance of spinopelvic balance and its implications for clinical outcomes after spinal arthrodesis has been reported in recent studies. However, little is known about the relationship between adjacent-segment disease (ASD) after lumbar arthrodesis and spinopelvic alignment. The purpose of this study was to clarify the relationship between spinopelvic radiographic parameters and symptomatic ASD after L4–5 single-level posterior lumbar interbody fusion (PLIF).
This was a retrospective 1:5 matched case-control study. Twenty patients who had undergone revision surgery for symptomatic ASD after L4–5 PLIF and had standing radiographs of the whole spine before primary and revision surgeries were enrolled from 2005 to 2012. As a control group, 100 age-, sex-, and pathology-matched patients who had undergone L4–5 PLIF during the same period, had no signs of symptomatic ASD for more than 3 years, and had whole-spine radiographs at preoperation and last follow-up were selected. Mean age at the time of primary surgery was 68.9 years in the ASD group and 66.7 years in the control group. Several radiographic spinopelvic parameters were measured as follows: sagittal vertical axis (SVA), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), and segmental lordosis at L4–5 (SL) in the sagittal view, and C7–central sacral vertical line (C7-CSVL) in the coronal view. Radiological parameters were compared between the groups.
No significant change was found between pre- and postoperative radiographic parameters in each group. In terms of preoperative radiographic parameters, the ASD group had significantly lower LL (40.7° vs 47.2°, p < 0.01) and significantly higher PT (27° vs 22.9°, p < 0.05) than the control group. SVA ≥ 50 mm was observed in 10 of 20 patients (50%) in the ASD group and in 21 of 100 patients (21%, p < 0.01) in the control group. PI-LL ≥ 10° was noted in 15 of 20 patients (75%) in the ASD group and in 40 of 100 patients (40%, p < 0.01) in the control group on preoperative radiographs. Postoperatively, the ASD group had significantly lower TK (22.5° vs 30.9°, p < 0.01) and lower LL (39.3° vs 48.1°, p < 0.05) than the control group had. PI-LL ≥ 10° was seen in 15 of 20 patients (75%) in the ASD group and in 43 of 100 patients (43%, p < 0.01) in the control group.
Preoperative global sagittal imbalance (SVA > 50 mm and higher PT), pre- and postoperative lower LL, and PI-LL mismatch were significantly associated with ASD. Therefore, even with a single-level PLIF, appropriate SL and LL should be obtained at surgery to improve spinopelvic sagittal imbalance. The results also suggest that the achievement of the appropriate LL and PI-LL prevents ASD after L4–5 PLIF.
近期研究报道了脊柱骨盆平衡的重要性及其对脊柱融合术后临床疗效的影响。然而，对于腰椎融合术后相邻节段疾病（ASD）与脊柱骨盆对线之间的关系却知之甚少。本研究的目的是阐明L4-5单节段后路腰椎椎间融合术（PLIF）后脊柱骨盆影像学参数与症状性ASD之间的关系。
这是一项回顾性1:5匹配病例对照研究。从2005年至2012年纳入20例L4-5 PLIF术后因症状性ASD接受翻修手术且在初次手术和翻修手术前均有全脊柱站立位X线片的患者。作为对照组，选择100例年龄、性别和病理相匹配的患者，这些患者在同一时期接受了L4-5 PLIF手术，3年多来没有症状性ASD的迹象，且在术前和末次随访时有全脊柱X线片。ASD组初次手术时的平均年龄为68.9岁，对照组为66.7岁。测量了以下几个影像学脊柱骨盆参数：矢状垂直轴（SVA）、胸椎后凸（TK）、骶骨倾斜度（SS）、骨盆倾斜度（PT）、骨盆入射角（PI）、腰椎前凸（LL）以及矢状面L4-5节段前凸（SL），冠状面测量C7-骶骨中心垂直线（C7-CSVL）。对两组间的影像学参数进行比较。
每组术前和术后影像学参数均未发现显著变化。就术前影像学参数而言，ASD组的LL显著低于对照组（40.7°对47.2°，p < 0.01），PT显著高于对照组（27°对22.9°，p < 0.05）。ASD组20例患者中有10例（50%）观察到SVA≥50 mm，对照组100例患者中有21例（21%，p < 0.01）观察到。术前X线片上，ASD组20例患者中有15例（75%）PI-LL≥10°，对照组100例患者中有40例（40%，p < 0.01）。术后，ASD组的TK显著低于对照组（22.5°对30.9°，p < 0.01），LL也低于对照组（39.3°对48.1°，p < 0.05）。ASD组20例患者中有15例（75%）PI-LL≥10°，对照组100例患者中有43例（43%，p < 0.01）。
术前整体矢状面失衡（SVA>50 mm和更高的PT）、术前和术后较低的LL以及PI-LL不匹配与ASD显著相关。因此，即使是单节段PLIF，手术时也应获得合适的SL和LL以改善脊柱骨盆矢状面失衡。结果还表明，实现合适的LL和PI-LL可预防L4-5 PLIF术后的ASD。
