Tonsillar herniation and the cervical spine: a morphometric study of 172 patients

The range of motion at C1-C2 was significantly smaller in the TH group (5.4°) than in the Non-TH group (8.4°) in patients over 70 years of age. The level of narrowing of the dura diameter at C5/C6 was significantly higher (P = 0.029) in the TH group (23.3%) than in the Non-TH group (13.4%) in patients over 70 years of age. The cervical alignment was similar in both groups for all age groups.