CT - Functional Diagnostics of the Rotatory Instability of the Upper Cervical Spine: Part 2. An Evaluation on Healthy Adults and Patients with Suspected InstabilityDVORAK, JIRI, MD*,†; HAYEK, JOHN, MD†; ZEHNDER, ROLF, PhD‡Spine: October 1987 - Volume 12 - Issue 8 - p 726-731 Original Article: PDF Only Buy Abstract Author InformationAuthors Nine healthy adults and 43 patients with cervical spine injury were examined by using functional (computerized tomography) CT scanning. The ranges of axial rotation at the levels occiput C0–C1, C1–C2, and C2–C3 were measured. A rotation at C0–C1 greater than 8°; at C1–C2, 56°; or a right-left difference C0–C1 greater than 5° and C1–2 greater than 8° indicates hypermobility. A rotation at segment C1–C2 of less than 28° indicates hypomobility. Surgical stabilization of rotatory instability could be considered as a possible therapeutic procedure. *From the Department of Neurology, University of Berne, Inselspital, Berne, Switzerland †From the Department of Neurology, Klinik W. Schulthess, Zurich ‡From the AO/ASIF Documentation Center, Berne, Switzerland © Lippincott-Raven Publishers.