Patterns of Cervical Disc Degeneration: Analysis of Magnetic Resonance Imaging of Over 1000 Symptomatic Subjects

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The aim of this study was to evaluate cervical disc degeneration on magnetic resonance imaging (MRI) in a large population of symptomatic patients and to provide baseline data on the pattern of degeneration in order to understand how the cervical spine ages. METHODS: We performed a cross-sectional study of 1059 patients who underwent upright cervical MRI for neck pain with and without neurological symptoms. A total of 6354 cervical discs from C2/3 to C7/T1 were evaluated. Cervical disc degeneration was evaluated on T2-weighted MRI and graded into 4 categories (Grades 0-III). Positive degeneration was defined as greater than Grade II. The correlation between age and total grade of degeneration of each patient was evaluated, as well as the prevalence and pattern of degeneration. RESULTS: The average number of degenerated disc levels and the total grade of cervical disc degeneration significantly increase with age. In the patient group with 1-level degeneration, C5/6 was the most common degenerated level followed by C4/5 and C6/7. In the group with 2-level degeneration, C5/6 & C6/7 was most common followed by C4/5 & C5/6 and C3/4 & C4/5. Skip level degeneration was significantly rarer than contiguous level degeneration, and C7/T1 and C2/3 were the most unlikely to degenerate in multilevel degeneration. CONCLUSION: Disc degeneration is most common in the middle cervical spine (C5/6) and progresses to contiguous levels, except for C7/T1 and C2/3. This pattern may play a role in adjacent-level disc degeneration associated with spinal fusion.