Ando Kei, Imagama Shiro, Ito Zenya, Kobayashi Kazuyoshi, Ukai Junichi, Muramoto Akio, Shinjo Ryuichi, Matsumoto Tomohiro, Nakashima Hiroaki, Ishiguro Naoki
From the Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
J Spinal Disord Tech. 2014 May;27(3):181-4. doi: 10.1097/BSD.0b013e3182a3589d.
Retrospective clinical study.
To investigate, using multislice CT images, how thoracic ossification of the posterior longitudinal ligament (OPLL) changes with time after thoracic posterior fusion surgery.
Few studies have evaluated thoracic OPLL preoperatively and post using computed tomography (CT).
The subjects included 19 patients (7 men and 12 women) with an average age at surgery of 52 years (38-66 y) who underwent indirect posterior decompression with corrective fusion and instrumentation at our institute. Minimum follow-up period was 1 year, and averaged 3 years 10 months (12-120 mo). Using CT images, we investigated fusion range, preoperative and postoperative Cobb angles of thoracic fusion levels, intraoperative and postoperative blood loss, operative time, hyperintense areas on preoperative MRI of thoracic spine and thickness of the OPLL on the reconstructed sagittal, multislice CT images taken before the operation and at 3 months, 6 months and 1 year after surgery. The basic fusion area was 3 vertebrae above and below the OPLL lesion.
The mean operative time was 7 hours and 48 min (4 h 39 min-10 h 28 min), and blood loss was 1631 mL (160-11,731 mL). Intramedullary signal intensity change on magnetic resonance images was observed at the most severe ossification area in 18 patients. Interestingly, the rostral and caudal ossification regions of the OPLLs, as seen on sagittal CT images, were discontinuous across the disk space in all patients. Postoperatively, the discontinuous segments connected in all patients without progression of OPLL thickness by 5.1 months on average.
All patients needing surgery had discontinuity across the disk space between the rostral and caudal ossified lesions as seen on CT. This discontinuity was considered to be the main reason for the myelopathy because a high-intensity area on magnetic resonance imaging was seen in 18 of 19 patients at the same level. Rigid fixation with instrumentation may allow the discontinuous segments to connect in patients without a concomitant thickening of the OPLL.
回顾性临床研究。
利用多层CT图像，研究胸椎后纵韧带骨化（OPLL）在胸椎后路融合手术后随时间的变化情况。
很少有研究使用计算机断层扫描（CT）对胸椎OPLL进行术前和术后评估。
研究对象包括19例患者（7例男性和12例女性），手术时平均年龄为52岁（38 - 66岁），在我院接受了间接后路减压、矫正融合及内固定手术。最短随访期为1年，平均为3年10个月（12 - 120个月）。利用CT图像，我们研究了融合范围、胸椎融合节段术前和术后的Cobb角、术中及术后失血量、手术时间、胸椎术前MRI上的高强度区域以及手术前、术后3个月、6个月和1年所拍摄的重建矢状位多层CT图像上OPLL的厚度。基本融合区域为OPLL病变上下各3个椎体。
平均手术时间为7小时48分钟（4小时39分钟 - 10小时28分钟），失血量为1631毫升（160 - 11731毫升）。18例患者在最严重的骨化区域观察到磁共振图像上的髓内信号强度变化。有趣的是，矢状位CT图像上可见，所有患者OPLL的头侧和尾侧骨化区域在椎间盘间隙处均不连续。术后，所有患者的不连续节段均相连，OPLL厚度平均在5.1个月时无进展。
所有需要手术的患者在CT上均显示头侧和尾侧骨化病变之间的椎间盘间隙不连续。这种不连续性被认为是脊髓病的主要原因，因为19例患者中有18例在同一水平的磁共振成像上可见高强度区域。器械的坚强固定可能使不连续节段在患者中相连，而OPLL无增厚。
