[Diagnosis of hyper- and hypomotility of the upper cervical spine using functional computerized tomography]

At present, there are few methods that are of any assistance in evaluating the ligaments of the upper cervical spine. It is obvious that a lesion of these ligaments could result in instability of the cranial cervical junction. Nine healthy adults and 45 patients with suspected rotatory instability of the upper cervical spine after trauma were examined using functional CT-scans. After CT scans of the upper cervical spine had been obtained with the patient in a neutral position, the head was passively rotated to the left and right and held in these positions by adhesive tape. CT scans were performed for the left and right rotation. The range of axial rotation was measured in relation to the neutral position at the level of the occiput, atlas and axis using identical bony landmarks. A mean rotation of 4.2 degrees to the right and 3.8 degrees to the left was measured at the occiput/atlas level. The mean difference between left and right rotation in individual patients was 2 degrees. The mean rotation of C1-2 was 41.8 degrees to the right and 44.3 degrees to the left. The mean difference between left and right rotation was 2.8 degrees. A 98% confidence interval for allocating a pathological case to the distribution of healthy adults was defined. According to this rule, occiput/atlas rotation of 8 degrees or more, C1-2 rotation of 56 degrees or more, a left/right OCC/C1 difference of 5 degrees or more and a left/right C1-2 difference of 8 degrees or more were considered to be pathological.(ABSTRACT TRUNCATED AT 250 WORDS)