Analysis of trends in lumbar disc degeneration using kinematic MRI

OBJECTIVE The aim of the current study was to classify and analyze trends in lumbar disc degeneration across age, sex, and disc level using weightbearing kinematic MRI. MATERIALS AND METHODS Between January 2019 and July 2019, 1198 cases were retrospectively analyzed with kinematic MRI. Patients were divided into 5 groups based on age (20-29, 30-39, 40-49, 50-59, and 60+) and evaluated using the Pfirrmann classification to assess for disc degeneration at 5 vertebral levels: L1/2, L2/3, L3/4, L4/5, and L5/S1. Trends in degeneration were analyzed with regression and time series. RESULTS The L5/S1 vertebral disc had the highest prevalence of severe degeneration across all age groups. The most common multi-level degeneration combinations were L4/5 and L5/S1 for two levels and L3/4, L4/5, and L5/S1 for three levels. All vertebral levels showed significant difference in mean Pfirrmann grade among the age groups (p < 0.001 at all levels). Statistically significant differences in mean Pfirmmann grade among males and females were found only in ages 20-29 and 30-39, in which males showed more degeneration. CONCLUSION Our findings using kinematic MRI demonstrate that degeneration increases with age and is most severe in the L5/S1 disc. In multi-level degeneration the most prevalent combinations are those that are contiguous and include L5/S1. Young males were more likely to have degeneration than young females, but there was no significant difference from the fifth decade of life on.