Abstract / Summary
Abstract Background Kümmell’s disease can be treated with percutaneous vertebral augmentation or posterior pedicle screw fixation with cement augmentation, but clinicians lack a simple imaging-based rule for choosing between them. This study developed a surgery-directed classification system based on the kyphotic angle difference between standing radiography and supine CT (ΔKA) and the vertebral compression ratio. Methods We retrospectively reviewed 102 consecutive patients with Kümmell’s disease from a single center. Logistic regression identified independent predictors of surgical approach. ROC curve analysis and Youden’s index determined cutoff values. Cohen’s κ assessed interobserver reliability. Clinical outcomes were reviewed in 77 patients with follow-up. Results ΔKA (OR 1.966, 95% CI 1.382–2.797, p < 0.001) and compression ratio (OR 1.086, 95% CI 1.014–1.162, p = 0.018) independently predicted surgical strategy; age (OR 0.798, 95% CI 0.680–0.936, p = 0.006) was also retained. Cutoffs were 8° for ΔKA (sensitivity 0.920, specificity 0.865; AUC 0.948) and 43% for compression ratio (sensitivity 0.640, specificity 0.865; AUC 0.823). Interobserver reliability was substantial (κ = 0.87). Type A (ΔKA < 8°, compression ratio < 43%) is treated with vertebral augmentation; Type B (ΔKA < 8°, compression ratio ≥ 43%) and Type C (ΔKA ≥ 8°) receive posterior screw fixation with cement augmentation. Conclusions The SDTCM-K system links two routine radiographic measurements to a concrete surgical plan. It adds to the literature a decision-oriented classification with validated cutoffs, which existing morphological staging systems do not provide.