退变性脊柱侧凸患者的下肢代偿对矢状面整体平衡的影响

The compensatory pattern of sagittal profile in patients with degenerative scoliosis

中文关键词:  退变性脊柱侧凸  下肢代偿  EOS影像系统  全身矢状面

英文关键词:Degenerative scoliosis  Lower limb compensation  EOS imaging system  Whole body sagittal alignment

中文摘要:

  【摘要】目的:通过比较站立位全身EOS片上有下肢代偿和无下肢代偿的退变性脊柱侧凸（degenerative scoliosis，DS）患者矢状面的影像学参数，研究下肢代偿对DS患者全身矢状面整体平衡的影响，并进一步探讨全身矢状面具体的代偿模式。方法：本研究纳入了2017年10月~2018年2月在我院就诊的DS患者43例，所有患者在术前均摄全身EOS片。测量经典矢状面参数[胸椎后凸角（TK）、腰椎前凸角（LL）、骨盆入射角（PI）、骶骨倾斜角（SS）、骨盆倾斜角（PT）、矢状面平衡（SVA）]以及矢状面上解剖学标志之间的水平距离（horizontal offset）：颅骨质心（the cranial center of mass，CCOM）与脚踝（ankle）中心之间的水平距离（Cr-A）；C2椎体质心与ankle中心之间的水平距离（C2-A）；C7椎体质心与ankle中心之间的水平距离（C7-A）和C2椎体质心与股骨头（femoral head）中心之间的水平距离（C2-F）。并测量膝关节角（knee angle，KA）。所有患者根据KA是否大于3°分为有下肢代偿患者组与无下肢代偿组。通过独立样本t检验比较两组患者各矢状面参数之间的差异。结果：共有20例无下肢代偿的DS患者和23例有下肢代偿的DS患者纳入本研究。两组患者PI、PI-LL的差异均无统计学意义（P=0.748，P=0.765）。下肢代偿患者的PT为24.8°±10.4°，大于无下肢代偿患者的19.3°±6.0°（P<0.05）。而有下肢代偿患者的TK为21.9°±14.0°，大于无下肢代偿患者的12.2°±7.1°（P<0.05）。有下肢代偿患者的KA大于无下肢代偿的患者（5.7°±1.0° vs 1.6°±1.0°）（P<0.05），两组之间的差值平均为4.1°。存在下肢代偿患者的SVA为62.2±38.0mm，小于无下肢代偿患者的90.9±24.7mm（P<0.05）。两组患者C2-A的差异也存在统计学意义，有下肢代偿患者的C2-A小于无下肢代偿的患者（52.2±8.1mm vs 68.6±26.3mm）（P<0.05），两组之间的差值平均为16.4mm。结论：DS患者能够通过下肢代偿使得全身矢状面整体处于更加有利的平衡状态，而无下肢代偿患者可能由于骨盆后旋受限，往往需要减少胸椎后凸来代偿矢状面整体失衡趋势。

英文摘要:

  【Abstract】 Objectives: To investigate the effects of lower limb compensation on full-body sagittal alignment, and to explore the whole body compensatory pattern in degenerative scoliosis(DS), by comparing the parameters of patients with and without lower limb compensation on standing EOS full body films. Methods: Forty-three DS patients in our hospital between October 2017 and February 2018 were included. All patients underwent full body EOS films preoperatively. The following sagittal parameters were recorded: thoracic kyphosis, lumbar lordosis, pelvic incidence, sacral slope, pelvic tilt and sagittal vertical axis. The horizontal offset between anatomical landmarks on the sagittal plane was measured, including the CCOM to the ankle center(Cr-A), the C2 to the ankle center(C2-A), the C7 to the ankle center(C7-A) and the C2 to the femoral head center(C2-F). The knee angle(KA) was also measured. All patients were divided into patients with lower limb compensation group and patients without lower limb compensation group according to whether KA was greater than 3 degrees. The differences of sagittal parameters between patients with and without compensation were compared by the independent sample t test. Results: A total of 20 DS patients without lower limb compensation and 23 DS patients with lower limb compensation were included in this study. There was no significant difference of PI or PI-LL between the two groups. The PT of patients with lower extremity compensation was 24.8°±10.4°, which was significantly greater than that of patients without lower limb compensation. The TK of patients with lower extremity compensation was 21.9°±14.0°, which was significantly higher than that of patients without lower extremity compensation. The KA of patients with lower extremity compensation was 5.7°±1.0°, which was significantly higher than that of patients without lower extremity compensation. The SVA of patients with lower limb compensation(62.2±38.0mm) was significantly smaller than that of patients without lower limb compensation(90.9±24.7mm). The difference of C2-A between the two groups was also statistically significant. The horizontal offset of patients with lower extremity compensation was significantly smaller than that of patients without lower extremity compensation(52.2±8.1mm vs 68.6±26.3mm), the difference was averaged at 16.4mm. Conclusions: DS patients can make the sagittal profile of the whole body in a more favourable balance state through lower limb compensation, while patients without lower limb substitution may need to reduce the overall imbalance trend of thoracic kyphosis compensation sagittal plane due to pelvic posterior rotation limitation.