Radiographic standing cervical segmental alignment in adult volunteers without neck symptoms.

STUDY
DESIGN: A radiographic evaluation of standing cervical and global sagittal alignment in 100 adult volunteers with no neck or radicular arm symptoms was undertaken.
OBJECTIVES: To document and define cervical standing lateral alignment and balance in a volunteer population without cervical problems. SUMMARY OF BACKGROUND DATA: Minimal data exist on cervical segmental sagittal alignment distributions in stance.
METHODS: Radiographic measures of spinal alignment were collected and statistically analyzed.
RESULTS: Data were categorized into two age- and sex-matched groups. Group 1 had no cervical or lumbar symptoms. Group 2 had no cervical symptoms, but had lumbar symptoms. Mean total and segmental cervical alignment distributions were not statistically different between groups. Mean total cervical lordosis in stance for the entire group was -40.0 +/- 9.7 degrees. Thoracic and lumbar alignment were within previously reported measures and not statistically different between groups. Plumb line markers at C7 and sacral reference points were not statistically different between groups. Pearson correlations revealed that cervical sagittal plane alignment vaired inversely with thoracic alignment. Independent orthopedists noted cervical osteoarthritis was present in 17% of each group of volunteers with substantial kappa agreement (0.73) between observers. Intraobserver and interobserver reliability of sagittal alignment measures of 30 randomly remeasured radiographs revealed strong correlation between observations.
CONCLUSIONS: No differences in total cervical lordosis were noted between cervical asymptomatic volunteers with or without low back pain. Most cervical lordosis occurred at the C1-C2 level in stance, whereas only 6 degrees (15%) occurred at the lowest three cervical levels (C4-C7). Changes in cervical lordosis correlated inversely with changes in thoracic alignment.