Katsuura Yoshihiro, Lemons Alex, Lorenz Eileen, Swafford Rachel, Osborn James, Cason Garrick
University of Tennessee Department of Orthopaedic Surgery, Chattanooga, TN.
Erlanger Hospital, Department of Radiology, Chattanooga, TN.
Int J Spine Surg. 2017 Apr 5;11(2):13. doi: 10.14444/4013. eCollection 2017.
Restoration and maintenance of cervical lordosis is an important clinical parameter in spine surgery. The purpose of this study was to determine the extent to which a multilevel anterior cervical discectomy and fusion (ACDF: greater than 3 levels) procedure restores cervical lordosis and the affect of increasing lordosis on sagittal vertical axis.
We performed a retrospective radiographic analysis of 69 patients who underwent multilevel ACDF by 2 surgeons between 2013 and 2014. We measured the global and segmental sagittal alignment of the cervical spine using the cobb method at 4 time intervals (preop, post op 4wks, 10wks and 6 months) as well as the sagittal vertical axis (SVA) using both a C1-S1 and C7-S1 plumb line methods at 2 time intervals (preop and post op 4wks). Radiographs were measured by three reviewers.
Interrater reliability was good to excellent for all measurements. Cervical lordosis significantly increased from preop 10.26° to 4 weeks postop 19.44° and was maintained up to 6 months 19.34 (p<0.0005). Segmental cervical lordosis was also significantly increased from preop 8.22° to post op at 4 weeks (20.26°) and was maintained at post op 10weeks 20.30° and post op 6 months 19.56° (p<0.0005). C7-S1 SVA and C1-S1 SVA also significantly increased from 12.04mm preop to 27.49mm post op 4 wks (p<0.0005) and -1.93mm preop to 8.67mm post op (p<0.0005) respectively. A change in C2-C7 lordosis positively correlated with a change in C7-SVA and C1-SVA (r=0.37, P<0.005, and r=0.312, p<0.05 respectively).
Multilevel ACDF significantly increases and maintains both segmental and global cervical lordosis up to 6 months after surgery. Increasing C2-C7 global lordosis is correlated with increasing positive sagittal vertical axis. Level of evidence: IV.
颈椎生理前凸的恢复和维持是脊柱外科手术中的一个重要临床参数。本研究的目的是确定多节段颈椎前路椎间盘切除融合术（ACDF：大于3节段）恢复颈椎生理前凸的程度以及增加前凸对矢状垂直轴的影响。
我们对2013年至2014年间由2位外科医生实施多节段ACDF手术的69例患者进行了回顾性影像学分析。我们在4个时间点（术前、术后4周、10周和6个月）使用Cobb法测量颈椎的整体和节段矢状位对线，并在2个时间点（术前和术后4周）使用C1-S1和C7-S1铅垂线法测量矢状垂直轴（SVA）。影像学测量由3位评估者进行。
所有测量的评估者间信度均为良好至优秀。颈椎生理前凸从术前的10.26°显著增加至术后4周的19.44°，并维持至6个月时的19.34°（p<0.0005）。节段性颈椎生理前凸也从术前的8.22°显著增加至术后4周的20.26°，并在术后10周维持在20.30°，术后6个月维持在19.56°（p<0.0005）。C7-S1 SVA和C1-S1 SVA也分别从术前的12.04mm显著增加至术后4周的27.49mm（p<0.0005）以及从术前的-1.93mm增加至术后的8.67mm（p<0.0005）。C2-C7生理前凸的变化与C7-SVA和C1-SVA的变化呈正相关（r分别为0.37，P<0.005和0.312，p<0.05）。
多节段ACDF在术后6个月内显著增加并维持节段性和整体颈椎生理前凸。C2-C7整体前凸的增加与矢状垂直轴的正向增加相关。证据等级：IV级。
