Development and validation of a multilevel scale for quantitative assessment of mechanical exposure in traumatic spinal injuries

Abstract

Objective: To develop, theoretically substantiate, and perform primary validation of a multilevel (0–10 points) scale for quantitative assessment of the intensity of external mechanical impact in traumatic spinal injuries.

Materials and methods: The study design followed the COSMIN (Consensus-based Standards for the Selection of Health Measurement Instruments) principles for developing and validating medical measurement tools, ensuring an adequate level of scientific validity and reproducibility. A literature review (PubMed, Scopus, Web of Science, 1990–2025) enabled the identification of threshold values and modifying factors, including patient body mass, the transmission coefficient of impulse (T_land))), and the effective deceleration distance (S_land). Two datasets were used for validation: 40 standardized clinical vignettes and 52 real cases of thoracolumbar junction trauma (Th11–L2) with mandatory verification by computed tomography/magnetic resonance imaging. Construct and criterion validity, inter-rater reliability (ICC, κ), absolute reliability (SEM, MDC₉₅), diagnostic accuracy (ROC analysis), agreement level (Bland–Altman), and threshold stability were assessed.

Results: Based on comparative analysis of various approaches, the concept of “equivalent fall height” was proposed as a universal criterion of mechanical exposure in spinal trauma. An 11-level (0–10) quantitative scale and a spine-oriented derived metric were developed. Primary validation demonstrated high inter-rater agreement (ICC(2,1): 0.84 for the basic indicator and 0.79 for the spinal-oriented one; ICC(2,k): 0.95 and 0.92), acceptable absolute precision (SEM 0.80–0.95; MDC₉₅ 2.2–2.6 points), and stable thresholds (discrepancies exceeding ±1 level occurred in <7% of cases). The metrics showed significant associations with vertebral body wedge deformity (r=0.58), spinal canal compromise (r=0.49), and ordinal injury severity by AO Spine (ρ=0.62; p<0.001). In logistic modeling, each additional 1 m in equivalent fall height nearly doubled the odds of burst/unstable injuries (OR=1.85; 95% CI 1.45–2.38). The diagnostic performance of the scale was confirmed (AUC=0.82) for identifying vertebral fractures (optimal threshold ≈1.3 m; sensitivity – 0.76; specificity – 0.72).

Conclusions: The proposed scale provides a quantitative, mass-neutral, and clinically interpretable measure of the “event severity,” complements morphological classifications, enhances risk stratification, and can be applied for patient triage, diagnostic planning, and multicenter research.