An observational study of quality of motion in the ageing cervical spine: Sequence of segmental contributions in dynamic fluoroscopy recordings.

Abstract

Introduction: The term ‘physiological motion of the spine’ is commonly used, although there is no proper definition of normal, physiological spine motion. Segmental range of motion (sROM) is commonly used but inter- and intra-observer variability is large. Previous work has revealed a consistent sequence of segmental contributions in the cervical spine from dynamic fluoroscopy recordings in 80-90% of healthy individuals. The mean age of these individuals was 23 years (±2.6). Age has been shown to be associated with a 0.11˚ decrease of sROM per year, which means 5˚ decrease in motion of the total subaxial cervical spine for every 10 years of ageing. Therefore, it is of interest to study whether this sequence remains present in older people. The primary objective is to investigate if the previously defined normal sequence of cervical segmental contributions in dynamic fluoroscopy recordings in young asymptomatic individuals is also present in asymptomatic individuals between 55 and 70 years of age. Secondary objective: assessment of sROM and cervical sagittal alignment. Materials and Methods: Dynamic extension cinematographic recordings of the cervical spine were made in healthy asymptomatic individuals aged 55-70 years old. Individuals with a score of 4 or less on the Neck Disability Index (NDI), and without severe degenerative changes based on a Kellgren’s score of 3 or less were included. Two recordings were made with a two-week interval between recordings (T1 and T2). Segmental rotation of each individual segment within the range from C4 to C7 was plotted against the cumulative rotation in C4 -C7 to describe the sequence of segmental contributions. Results: A total of 10 individuals were included, resulting in 20 recordings. The average age of the study sample was 61 years. The predefined normal sequence of motion was found in 10% in T1 and 0% in T2 of individuals. sROM and total ROM (tROM) were low in all patients. Pearson correlation coefficients did not show a statistically significant correlation between sagittal alignment, degeneration and sROM in the respective segments, nor between cervical lordosis and tROM. Conclusion: This study shows that ageing is not only associated with a decrease in ROM, but also with a change in motion patterns, as observed in healthy asymptomatic individuals. The altered contribution of the cervical segments during extension appears not to be caused by degeneration or neck pain.