Trends and patterns of thoracic intervertebral disc degeneration in symptomatic subjects: a magnetic resonance imaging analysis.

Abstract

This study aimed to analyse the trends and patterns of IVD degeneration in different age groups at each level of the thoracic spine. This cross-sectional MRI study included 1000 symptomatic patients who had undergone upright thoracic spine MRI. A total of 13,000 thoracic IVDs from C7/T1 to T12/L1 were classified into five grades using Pfirrmann classification. Patients were divided according to their ages into five groups (n = 200/group). The severity and pattern of IVD degeneration were analysed in each age group. A predictive model of the severity and pattern of IVD degeneration in each age group was proposed. The total grade of IVD degeneration and the number of degenerated levels increased with increasing age (P < 0.001). The most common degenerated level was T6/7 (13.3%), while the least common degenerated level was T12/L1 (1.8%). The most common grades were grade I in group 1 (60.5%), grade II in groups 2 (39%) and 3 (37.3%), and grade III in groups 4 (42.5%) and 5 (44.6%). Adjacent-level degenerations were more common than skip-level degenerations. Severe disc degeneration (Pfirrmann grades IV or V) could be predicted to occur more in group 5 (patients with 60 years and above) (margin = 0.79, 95% CI = 0.73-0.84, P < 0.001). The severity of thoracic IVD degeneration and the number of degenerated levels increased with age. Disc degeneration was more accelerated in the mid-thoracic spine. Adjacent-level degeneration was more common than skip-level degenerations.