Vertebra C4
Vertebra CIV
- Related terms: C4
Definition
The cervical vertebra C4 (4th cervical vertebra) is a typical cervical vertebra with several distinct anatomical features. It has a small body, a large vertebral foramen, and transverse processes that contain transverse foramina for the passage of the vertebral arteries. The spinous process of C4 is often bifid, which is a common characteristic of cervical vertebrae.[1]
The uncinate processes of C4 are relatively high, measuring approximately 5.8 to 6.1 mm, which is significant for the involvement in uncovertebral joints and potential nerve root compression.[2] The anteroposterior diameter of the intervertebral foramina at the C4 level is smaller compared to C3 and C7, which can contribute to nerve root compression in cases of cervical spondylosis.[2]
The C4 vertebra also plays a role in the alignment of the cervical spine. The slope of the C4 inferior endplate remains relatively constant under physiological conditions, making it a benchmark for assessing cervical sagittal alignment.[3]
In terms of surface anatomy, the thyroid cartilage is a landmark for the C4-C5 disc space, which can be useful in clinical practice for localization during procedures.[4]
References
1.Shape Analysis of the Cervical Spinous Process.Greiner TM.Clinical Anatomy (New York, N.Y.). 2017;30(7):894-900. doi:10.1002/ca.22948.
2.Anatomic Considerations for Uncovertebral Involvement in Cervical Spondylosis.Ebraheim NA, Lu J, Biyani A, Brown JA, Yeasting RA.Clinical Orthopaedics and Related Research. 1997;(334):200-6.
3.C4 Constant Vertebra: A Novel Benchmark of Physiological Cervical Sagittal Alignment.Xu H, Gong Z, Yang Y, et al.European Spine Journal : Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2024;33(3):1195-1204. doi:10.1007/s00586-023-08100-w.
4.History of Cervical Spine Localization: Surface Landmarks.Johnson MD, Schwieterman W, Bugada M, et al.World Neurosurgery. 2024;:S1878-8750(24)01824-2. doi:10.1016/j.wneu.2024.10.119.
