J Korean Neurosurg Soc.  2012 Oct;52(4):300-305. 10.3340/jkns.2012.52.4.300.

Anatomical Morphometric Study of the Cervical Uncinate Process and Surrounding Structures

• Kim SH
• Lee JH
• Kim JH
• Chun KS
• Doh JW
• Chang JC

• KMID: 2190644
• DOI: http://doi.org/10.3340/jkns.2012.52.4.300

Abstract

OBJECTIVE
The purpose of this study is to elucidate the anatomic relationships between the uncinate process and surrounding neurovascular structures to prevent possible complications in anterior cervical surgery.
METHODS
Twenty-eight formalin-fixed cervical spines were removed from adult cadavers and were studied. The authors investigated the morphometric relationships between the uncinate process, vertebral artery and adjacent nerve roots.
RESULTS
The height of the uncinate process was 5.6-7.5 mm and the width was 5.8-8.0 mm. The angle between the posterior tip of the uncinate process and vertebral artery was 32.2-42.4degrees. The distance from the upper tip of the uncinate process to the vertebral body immediately above was 2.1-3.3 mm, and this distance was narrowest at the fifth cervical vertebrae. The distance from the posterior tip of the uncinate process to the nerve root was 1.3-2.0 mm. The distance from the uncinate process to the vertebral artery was measured at three different points of the uncinate process : upper-posterior tip, lateral wall and the most antero-medial point of the uncinate process, and the distances were 3.6-6.1 mm, 1.7-2.8 mm, and 4.2-5.7 mm, respectively. The distance from the uncinate process tip to the vertebral artery and the angle between the uncinate process tip and vertebral artery were significantly different between the right and left side.
CONCLUSION
These data provide guidelines for anterior cervical surgery, and will aid in reducing neurovascular injury during anterior cervical surgery, especially in anterior microforaminotomy.

Keyword

Anterior cervical surgery; Foraminotomy; Uncinate process, Vertebral artery; Nerve root

MeSH Terms

Adult
Cadaver
Cervical Vertebrae
Female
Foraminotomy
Humans
Spine
Vertebral Artery

Figure

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  Fig. 1 Photograph of a cadaveric specimen showing the height and width of the uncinate process. 1 : height of uncinate process, 2 : width of uncinate process, UP : uncinate process.

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  Fig. 2 Photograph of the transverse section through the disc level of the cervical spine showing the width of the uncinate process and the distance between the medial borders of the uncinate processes from each side of the vertebra. 1 : width of the uncinate process, 2 : distance between medial borders of uncinate processes at anterior margin, 3 : distance between medial borders of uncinate processes at midpoint, 4 : distance between medial borders of uncinate processes at posterior margin, UP : uncinate process.

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  Fig. 3 Photograph of the transverse section through the disc level of the cervical spine. The relationship of the vertebral artery and nerve root to the uncinate process is shown. 1 : angle between posterior tip of uncinate process and vertebral artery, 2 : shortest distance from posterior tip of uncinate process to nerve root, 3 : shortest distance from lateral wall of uncinate process to vertebral artery, NR : nerve root, UP : uncinate process, VA : vertebral artery.

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  Fig. 4 Photograph of the cadaveric specimen showing the distance from the most anteromedial point of the uncinate process to the vertebral artery and the distance from the tip of uncinate process to the vertebral artery. 1 : distance from the most anteromedial point of uncinate process to vertebral artery, 2 : distance from upper tip of uncinate process to vertebral artery, UP : uncinate process, VA : vertebral artery.

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  Fig. 5 Photograph of the cadaveric specimen showing Luschka joint space, corresponding to the distance from the upper tip of the uncinate process to the vertebral body immediately above it. UP : uncinate process, VB : vertebral body.

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