Applied anatomy of cervical dorsal rami nerve and its clinical significance

Objective:To provide anatomic basis for the diagnosis and treatment of the compression syndrome in cervical dorsal rami nerve.Methods:The origin,course,ramification,distribution of cervical dorsal rami nerve and its anatomic relationship with the adjacent tissues of the cervical vertebrae were observed on 20 adult embalmed cadavers(40 sides).Results:The C 1 dorsal ramus passed between atlas and occipital bone.The medial branch of C 2 dorsal ramus (the greater occipital nerve) passed through the osteo fibruos aperture near the superior nuchal line and spreaded across the top of the skull.After arising outside their respective intervertebral foramina,C 3～8 dorsal rami passed through osteo fibruos aperture,entered the osteo fibrous canal,passed through the tendious decussating fibers of the posterior muscles of neck and then supplied the cervical zygapophysial joints,the nuchal muscles and the occipital skin.The coordinate points of C 5 osteo fibrous apertures situated in 5.8 ±4.0 mm and 6.2±4.5 mm above the anterior tubercles of the same ordinal cervical vertebral transverse process and the coordinate points of C 6 osteo fibrous apertures situated in 12.2±2.5 mm and 13.6±3.9 mm behind the anterior tubercles of the same ordinal cervical vertebral transverse process.The coordinate points of C 5 and C 6 osteo fibrous canals' central points situated in 4.5±3.4 mm and 4.7±3.4 mm above the anterior tubercles of the same ordinal cervical vertebral transverse process respectively and situated in 18.4±3.3 mm and 18.2±4.3 mm behind the anterior tubercles of the same ordinal cervical vertebral transverse process respectively.Conclusion:The osteo fibrous apertures,osteo fibrous canal and the tendious decussating fibers of the nuchal muscles passed through by cervical dorsal rami are the anatomic basis of the cervical dorsal rami compression syndrome.