Akbar M, Almansour H, Diebo B, Adler D, Pepke W, Richter M
Zentrum für Wirbelsäulenchirurgie, Klinik für Orthopädie, Unfallchirurgie und Paraplegiologie, Universitätsklinikum Heidelberg, Schlierbacher Landstraße 200a, 69118, Heidelberg, Deutschland.
Department of Orthopaedic Surgery, Downstate Medical Center, State University of New York, New York (Brooklyn), USA.
Orthopade. 2018 Jun;47(6):460-466. doi: 10.1007/s00132-018-3580-1.
The cervical spine is very complex, and it allows the largest range of motion relative to the rest of the spine. The fundamental function of the cervical spine is to maintain the head balanced over the trunk and to maintain horizontal gaze. The cervical spine must be both stable and flexible to guarantee function. Changes of the sagittal profile of the cervical spine may affect function and quality of life. The relationship between full body alignment and maintaining gaze necessitates a thorough understanding of the cranio-spino-pelvic alignment as a component of balance.
Now the question is, what kind of sagittal profile does the cervical spine need for proper function? In the literature, normal sagittal alignment of the cervical spine is controversial. In general, there is the assumption that the alignment is lordotic. Does the data in the literature support this?
The present literature review supports the following facts: Ideal cervical spine alignment is mostly lordotic, but not always; ideal cervical spine alignment can be lordotic, neutral or kyphotic; ideal cervical spine alignment is driven by the necessity of supporting the head and maintaining horizontal gaze; the cervical spine is in harmony with regional alignment (thoracic kyphosis) and sagittal global alignment (SVA): TK (↑) → T1 Slope (↑) → CL (↑), TK (↓) → T1 Slope (↓) → CL (↓), SVA >50 mm: the cervical curve should be lordotic to maintain horizontal gaze, SVA <0 mm: the cervical curve should be kyphotic to maintain horizontal gaze.
颈椎非常复杂，相对于脊柱的其他部分，它允许最大的活动范围。颈椎的基本功能是保持头部在躯干上方平衡并维持水平注视。颈椎必须既稳定又灵活以保证功能。颈椎矢状面轮廓的改变可能会影响功能和生活质量。全身排列与维持注视之间的关系需要对作为平衡组成部分的颅-脊柱-骨盆排列有透彻的理解。
现在的问题是，颈椎正常功能需要怎样的矢状面轮廓？在文献中，颈椎正常矢状排列存在争议。一般来说，人们假定排列呈前凸。文献中的数据支持这一点吗？
当前的文献综述支持以下事实：理想的颈椎排列大多呈前凸，但并非总是如此；理想的颈椎排列可以是前凸、中立或后凸；理想的颈椎排列是由支撑头部和维持水平注视的必要性驱动的；颈椎与区域排列（胸椎后凸）和矢状面整体排列（矢状面垂直轴）协调一致：胸椎后凸（↑）→T1 斜率（↑）→颈椎前凸（↑），胸椎后凸（↓）→T1 斜率（↓）→颈椎前凸（↓），矢状面垂直轴＞50 毫米：颈椎曲度应为前凸以维持水平注视，矢状面垂直轴＜0 毫米：颈椎曲度应为后凸以维持水平注视。
