CUBD classification: A novel disc height-based grading system for uncovertebral joint degeneration with validated reliability and clinical correlations.

PURPOSE: This study aims to investigate a novel classification system for uncovertebral joint (UVJs) degeneration based on CT scans, referred to as the CUBD (Classification of Uncovertebral Joint Degeneration Based on Disc Height) system. Additionally, we assessed its reliability and internal consistency. METHODS: Quantitative assessment of CUBD classification was performed at C3-C7 levels using cervical computed tomography (CT), with concurrent evaluation of key degenerative parameters. The agreement between the ratings of all raters were evaluated using a two-way random model of intra-class correlation coefficients (ICC). RESULTS: A total of 93 hospitalized patients were included in this study, with a mean age of 50.34 ± 15.95 years, yielding a total of 744 UVJs (C3-C7) for analysis. The CUBD system demonstrated high internal consistency (κ = 0.83 > 0.80, ICC = 0.92, 95% CI: 0.923–0.933). At individual cervical spinal levels, the CUBD classification demonstrates statistically significant correlations with patient age, disc height, DHI, and JH, while showing no significant association with patient gender. Moreover, we observed a progressive decrease in the uncinate process angle with advancing degeneration and an exacerbation of local kyphosis, particularly at the C6/7 level. CONCLUSION: The disc height-based CUBD classification system for UVJs degeneration demonstrates robust interobserver reliability. This innovative grading framework not only establishes a novel conceptual paradigm for current UVJs degeneration research but also exhibits statistically significant correlations with global cervical degenerative changes, indicating substantial clinical applicability.