Cervical uncinate process: an anatomic study for anterior decompression of the cervical spine.

Morphometric evaluation of 54 dry cervical spines from C3 to C7 (a total of 270 cervical vertebrae) was performed to determine the bony boundaries of the uncinate process for resection of the uncinate process for access to posterolateral osteophytes or herniated disks at the time of anterior cervical diskectomy. The uncinate processes were significantly higher (p < 0.01) at the C4-C6 levels (5.8 +/- 1.1 mm to 6.1 +/- 1.3 mm) than at the C3 or C7 levels. The distance between the medial and lateral margins of the base of the uncinate process was significantly smaller (p < 0.01) at the C3 level (4.9 +/- 0.7 mm) than at the C7 level (6.3 +/- 0.7 mm). The anteroposterior diameter of the medial margin of the uncinate process decreased gradually from the C5 (12.5 +/- 1.5 mm) to C7 levels (11.6 +/- 1.3 mm) (p < 0.05). The inter-uncinate distance widened from the C3 (19.2 +/- 1.5 mm) to the C7 (24.6 +/- 2.1 mm) levels (p < 0.01). The mid-anteroposterior diameter of vertebral body increased gradually from the C3 (14.7 +/- 1.1 mm) to the C7 levels (16.1 +/- 1.5 mm) (p < 0.01). The width of the vertebra increased gradually from C3 to C7 (from 19.2 +/- 1.8 mm at C3 to 25.6 +/- 2.0 mm at C7) (p < 0.01). Knowledge of all the aforementioned data may be helpful during anterolateral cervical uncosectomy or uncoforaminotomy.