双开门椎管扩大成形术中椎板开门角度与椎管矢状径增加值的关系

Relationship between the angle of the opened lamina and the increase of sagittal canal diameter following double-door cervical laminoplasty

中文关键词:  颈椎  双开门椎管扩大成形术  椎板开门角度  椎管矢状径

英文关键词:Cervical spine  Laminoplasty  Laminoplasty opening angle  Spinal canal sagittal diameter

中文摘要:

  【摘要】 目的：探讨双开门椎管扩大成形术中椎板开门角度与椎管矢状径增加值之间的关系。方法：根据三角函数知识推理双开门椎管扩大成形术中椎板开门角度与椎管矢状径增加值之间关系的公式：d=h×（sinβ/sinα-1），α角是术前椎板与冠状面的夹角，β角是术后椎板与冠状面的夹角，h是双开门椎弓正中劈开点到两侧椎板开门处连线的垂直距离，d是术后椎管矢状径增加值。在2010年9月~2014年4月期间实施双开门椎管扩大成形术治疗多节段脊髓型颈椎病患者32例，其中C3～C7节段20例，C3～C6节段12例。术前及术后1周时在C3～C7节段各椎弓根层面的CT轴位片上应用PACS软件测量α、β、h、d。根据所测量的C3～C7各节段α、β、h值，应用公式计算相应节段的d值。应用配对t检验及Pearson相关分析比较各节段PACS软件直接测量所得的椎管矢状径增加值和公式计算得出的椎管矢状径增加值两组数据，以验证此公式的正确性。结果：C3~C7各节段公式计算得出的椎管矢状径增加值分别为5.15±0.47mm、5.39±0.47mm、5.22±0.37mm、5.25±0.25mm、4.35±0.35mm；PACS软件直接测量所得的椎管矢状径增加值分别为5.17±0.40mm、5.43±0.52mm、5.27±0.44mm、5.29±0.28mm、4.38±0.33mm；将各节段的两组数据分别进行配对t检验分析，t值分别为0.42，0.68，1.58，1.38，1.11，各节段的两组数据间差异均无统计学意义（P>0.05）；将各节段的两组数据分别进行Pearson相关性分析，r值分别为0.8953，0.8155，0.9159，0.7821，0.9238，各节段的两组数据间有相关关系（P<0.001）。结论：公式d=h×（sinβ/sinα-1）准确反映了双开门椎管扩大椎板成形术中椎板开门角度与椎管矢状径增加值之间的关系，在双开门椎管扩大成形术中，应用公式根据椎板开门的角度能预测椎管矢状径的增加值。

英文摘要:

  【Abstract】 Objectives: To clarify the relationship between the angle of the opened lamina and increase of sagittal canal diameter in double-door laminoplasty. Methods: The formula, d=h×(sinβ/sinα-1), describing the relationship between the angle of the opened lamina and increase of sagittal diameter was deduced by using trigonometry, α indicated preoperative lamina angle, β indicated the angle of the opened lamina, h indicated vertical distance which was from the split points before surgery to the wired of bilateral hinge gutters, d indicated the increase in sagittal diameter after double-door cervical laminoplasty, which was defined as the difference between post-surgical diameter and pre-surgical diameter. 32 patients with multilevel cervical spondylotic myelopathy underwent double-door cervical laminoplasty(C3-C7 in 20 patients and C3-C6 in 12 patients) in our institution between September 2010 and April 2014. At pre-operative and 1 week post-operative, axial CT was made at each pedicle level from C3 to C7 to measure the values of α, β, h by using software(picture archiving and communication system, PACS). The actual value of d was obtained by measuring the pre-and post-operative C3-C7 sagittal canal diameter by using PACS software. The computed value of d of C3-C7 in each patient was processing the formula d=h×(sinβ/sinα-1). The differences between the data obtained by actual measurement and the data computed by the formula were compared by the paired t test. The correlation between the data obtained by actual measurement and computed by the formula was assessed by Pearson′s correlation coefficient. The accuracy of the formula was assessed. Results: The computed value of d at C3-C7 was 5.15±0.47mm, 5.39±0.47mm, 5.22±0.37mm, 5.25±0.25mm, 4.35±0.35mm respectively; the actual measured value of d at C3-C7 using PACS measurement software was 5.17±0.40mm, 5.43±0.52mm, 5.27±0.44mm, 5.29±0.28mm, 4.38±0.33mm respectively. The data obtained by actual measurement and the data evaluated by the paired t test showed the value of t computed by the formula at C3-C7 was 0.42, 0.68, 1.58, 1.38, 1.11 respectively, which showed no significant difference(P>0.05). The value of r by Pearson correlation analysis computed by the formula at C3-C7 was 0.8953, 0.8155, 0.9159, 0.7821, 0.9238 respectively, which showed a very high degree of correlation(P<0.001). Conclusions: The formula accurately reveals the correlation between the angle of the opened lamina and the increase in sagittal canal diameter in double-door laminoplasty. Based on the angle of the opened lamina, increases in sagittal canal diameter following laminoplasty can be computed by using this formula.