Nakao Shin-ichi, Yoshida Munehito, Yamada Hiroshi, Hashizume Hiroshi
Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan.
J Spinal Disord Tech. 2010 Dec;23(8):e47-52. doi: 10.1097/BSD.0b013e3181cdd262.
A prospective study using a newly developed imaging diagnosis method to examine the patients with L5 radiculopathy.
To confirm the efficacy of a new 3-dimensional computed tomography (3D CT) imaging method to diagnose extraforaminal stenosis at the lumbosacral junction.
The lack of recognition of extraforaminal stenosis at the lumbosacral junction is a cause of failed back surgery syndrome. A clear method to diagnose this condition is essential.
The participants were 75 consecutive patients (mean age 69.5 y) with or without cauda equina symptoms who were treated by microendoscopic spinal surgery for L5 radiculopathy. The lesion responsible for the symptoms was identified by a combination of neurologic findings, selective radiculography, (3D MRI), and intraoperative neurophysiological findings. Multislice CT scanning was carried out preoperatively from the L1 vertebral body to the sacrum in all patients. The CT scan images were transferred to a remote computer workstation, and the reconstructed images were examined after surgery by an investigator blinded to the clinical diagnoses. In the reconstructed plane, we measured the minimum cross-sectional area of the de novo bony tunnel formed by the L5 transverse process, sacral ala, and L5 vertebral body, that is, lumbosacral bony tunnel (LSBT) and determined a cutoff value to diagnose extraforaminal stenosis. The shape of the LSBT was also evaluated in relation to the diagnosis.
In 3D CT analysis, the LSBT was found on the ipsilateral side in 51 of the 75 patients. The bony tunnel was outside the foramen in all patients diagnosed clinically with extraforaminal stenosis, but in only 60% of the patients without extraforaminal stenosis. The minimum cross-sectional area of the bony tunnel was significantly smaller in patients with an extraforaminal stenosis than in those without extraforaminal stenosis. The cutoff value was set at 0.8 cm2. The cross-sectional area was <0.8 cm2 in all patients with extraforaminal stenosis. The specificity of this diagnostic procedure was 89.6%, and the sensitivity was 100%. All true-positive cases had the spur-type shape of the bony tunnel, and all false-positive cases had the round-type shape.
All patients with extraforaminal stenosis had an LSBT. The minimum cross-sectional area of the bony tunnel was significantly smaller in patients with an extraforaminal lesion than in those without an extraforaminal lesion. 3D CT is a useful tool for diagnosing extraforaminal stenosis at the lumbosacral junction.
一项前瞻性研究，采用新开发的影像诊断方法检查L5神经根病患者。
证实一种新的三维计算机断层扫描（3D CT）成像方法诊断腰骶部椎间孔外狭窄的有效性。
对腰骶部椎间孔外狭窄认识不足是腰椎手术失败综合征的一个原因。明确诊断这种情况的方法至关重要。
研究对象为75例连续的L5神经根病患者（平均年龄69.5岁），有或无马尾神经症状，均接受了显微内镜下脊柱手术治疗。通过神经系统检查结果、选择性神经根造影、（3D MRI）以及术中神经生理学检查结果相结合来确定导致症状的病变部位。所有患者术前均进行从L1椎体至骶骨的多层CT扫描。将CT扫描图像传输至远程计算机工作站，术后由一名对临床诊断不知情的研究人员检查重建图像。在重建平面上，我们测量由L5横突、骶骨翼和L5椎体形成的新生骨隧道即腰骶骨隧道（LSBT）的最小横截面积，并确定诊断椎间孔外狭窄的临界值。还对LSBT的形状与诊断的关系进行了评估。
在3D CT分析中，75例患者中有51例在同侧发现了LSBT。临床上诊断为椎间孔外狭窄的所有患者，其骨隧道均在椎间孔外，但在无椎间孔外狭窄的患者中只有60%如此。椎间孔外狭窄患者的骨隧道最小横截面积明显小于无椎间孔外狭窄的患者。临界值设定为0.8平方厘米。所有椎间孔外狭窄患者的横截面积均<0.8平方厘米。该诊断方法的特异性为89.6%，敏感性为100%。所有真阳性病例的骨隧道为骨刺型，所有假阳性病例的骨隧道为圆形。
所有椎间孔外狭窄患者均有LSBT。椎间孔外有病变的患者其骨隧道最小横截面积明显小于无椎间孔外病变的患者。3D CT是诊断腰骶部椎间孔外狭窄的有用工具。
