Department of Orthopaedics, Peking University Third Hospital, No.49 Huayuan Bei Road, Beijing, 100191, China.
J Orthop Surg Res. 2020 Jul 6;15(1):243. doi: 10.1186/s13018-020-01762-y.
Although pelvic and related parameters have been well stated in lumbar developmental spondylolisthesis, cervical sagittal alignment in these patients is poorly studied, especially in high dysplastic developmental spondylolisthesis (HDDS). The purpose of this study is to investigate the sagittal alignment of the cervical spine in HDDS and how the cervical spine responds to reduction of spondylolisthesis.
Thirty-three adolescent patients with lumbar developmental spondylolisthesis who received preoperative and postoperative whole-spine x-rays were reviewed. They were divided into the HDDS group (n = 24, 13.0 ± 2.2 years old) and the low dysplastic developmental spondylolisthesis (LDDS) group (n = 9, 15.6 ± 1.9 years old). Spinal and pelvic sagittal parameters, including cervical lordosis (CL), were measured and compared between groups. In the HDDS group, the postoperative parameters were measured and compared with those before surgery.
HDDS group had a higher proportion of cervical kyphosis (70.8% vs. 22.2%, P = 0.019), and there was a significant difference in CL between the two groups (- 8.5° ± 16.1° vs. 10.5° ± 11.8°, P = 0.003). CL was correlated with the Dubousset's lumbosacral angle (Dub-LSA), pelvic tilt (PT), and thoracic kyphosis (TK). In the HDDS group, CL in patients with a kyphotic cervical spine was significantly improved after reduction of spondylolisthesis (- 16.4° ± 5.9° vs. - 3.6° ± 9.9°, P < 0.001). In the HDDS group, 46% (6/13) of the patients with postoperative Dub-LSA < 90° still had sagittal imbalance (sagittal vertical axis, [SVA] > 5 cm), while no sagittal imbalance was observed in patients with postoperative Dub-LSA > 90° (46% [6/13] vs. 0% [0/11], P = 0.016).
HDDS can lead to cervical kyphosis through a series of compensatory mechanisms. Reduction of spondylolisthesis and correction of lumbosacral kyphosis may correct the cervical kyphosis and normalize the overall spinal sagittal profile. Correction of Dub-LSA to above 90° might be used as an objective to better improve the sagittal alignment of the spine.
尽管骨盆和相关参数在腰椎发育性滑脱中已经得到了很好的描述，但这些患者的颈椎矢状位排列研究甚少，尤其是在高度发育性滑脱（HDDS）中。本研究的目的是探讨 HDDS 患者颈椎矢状位排列，并了解颈椎对滑脱复位的反应。
回顾了 33 例接受术前和术后全脊柱 X 线检查的青少年腰椎发育性滑脱患者。将患者分为 HDDS 组（n=24，年龄 13.0±2.2 岁）和低度发育性滑脱（LDDS）组（n=9，年龄 15.6±1.9 岁）。测量两组的脊柱和骨盆矢状位参数，包括颈椎前凸（CL）。在 HDDS 组中，测量并比较了术后参数与术前参数。
HDDS 组颈椎后凸的比例较高（70.8%比 22.2%，P=0.019），两组 CL 存在显著差异（-8.5°±16.1°比 10.5°±11.8°，P=0.003）。CL 与 Dubousset 腰骶角（Dub-LSA）、骨盆倾斜（PT）和胸椎后凸（TK）相关。在 HDDS 组中，颈椎后凸患者的 CL 在滑脱复位后显著改善（-16.4°±5.9°比-3.6°±9.9°，P<0.001）。在 HDDS 组中，术后 Dub-LSA<90°的患者中有 46%（6/13）仍存在矢状失平衡（SVA>5cm），而术后 Dub-LSA>90°的患者中无矢状失平衡（46%[6/13]比 0%[0/11]，P=0.016）。
HDDS 可通过一系列代偿机制导致颈椎后凸。滑脱复位和腰骶段矫正可纠正颈椎后凸，使脊柱整体矢状位排列正常化。将 Dub-LSA 矫正至 90°以上可能作为改善脊柱矢状位排列的客观指标。
