Intersegmental sagittal motion in the lower cervical spine and discogenic spondylosis: a preliminary study

The object of this investigation was to identify any correlation between discogenic spondylosis and the type of motion (normal, hypomobility, hypermobility, paradoxical motion) found in the sagittal plane of the intervertebral motion units of the lower cervical spine.

A case control study was performed from the files of 100 patients (ages 15-73) with cervical spine-related symptomatology at the Anglo-European College of Chiropractic Clinic.

The cases were randomly selected from a cohort of patients with normal radiographic anatomy who attended the clinic from 1987-1990 and were known to have cervical spine neutral, flexion and extension lateral radiographs taken.

Extended chi 2 was used to test the observed data.

The findings from both the flexion and extension films suggested that intervertebral motion units with and without varying severities of discogenic spondylosis did differ with respect to the type of motion exhibited there (flexion: chi 2 = 39.399, p < .001; extension: chi 2 = 45.7424, p < .001). Intervertebral motion units which had discogenic spondylosis had a greater likelihood of exhibiting motion abnormalities (flexion: chi 2 = 5.665, p < .01; extension: chi 2 = 6.178, p < .01), and all types of motion seemed to be dependent on its severity (flexion: chi 2 = 16.464, p < .01; extension: chi 2 = 15.954, p < .02). In general, normal motion occurred approximately 60% of the time when there was absent or mild discogenic spondylosis and decreased precipitously as moderate and severe amounts of discogenic spondylosis appeared. In global cervical flexion, when there was either little or no discogenic spondylosis and abnormal motion was present, intersegmental hypermobility was predominant. Hypomobility became predominant overall as moderate and severe discogenic spondylosis was found. In global cervical extension, for all severities of discogenic spondylosis when there was abnormal motion, intersegmental hypomobility was predominant. Also of note was the presence of paradoxical motion, which occurred in 11% of the intervertebral motion units without discogenic spondylosis [usually at the C7-T1 intervertebral motion unit (86%)].

From the data it can be concluded that there are trends which occur with differing amounts of discogenic spondylosis when considering intersegmental cervical sagittal motion. However, additional detailed study is required to corroborate the findings and determine what their clinical significance is.