Intervertebral Disc Abnormalities on MRI in Thoracolumbar High-Energy and Fragility Fractures Treated With the SpineJack®-System: A Secondary Analysis of a Single-Centre Cohort

Study Design Retrospective secondary analysis. Objectives To describe the frequency of concomitant disc abnormality on preoperative MRI in SpineJack®-treated thoracolumbar fractures and its association with fracture type and clinical parameters. Methods From our published SpineJack® cohort (310 fractures, 2014-2022), 204 fractures in 176 patients with preoperative MRI were analyzed. Discs were graded (Sander et al.) by two readers independently, then by consensus; fractures by AOSpine or OF type. Analyses used exact tests, Spearman correlation and Firth logistic regression; the OVF-versus-VCF comparison was adjusted for age and sex. Other analyses were exploratory. Results 119 fractures (58.3%) were OVFs (mean age 72.5 years) and 85 were VCFs (50.0 years). Superior, inferior and combined disc abnormality occurred in 68.1%, 58.3% and 53.9%. Superior abnormality was more frequent in OVFs than VCFs (73.9% vs 60.0%; crude OR 1.89, 95% CI 1.04-3.44), but not after adjustment (OR 1.29, 0.57-2.91). AOSpine type correlated with inferior disc grade in VCFs (ρ=0.247, p=0.023); OF type did not correlate with disc grade. Exploratory: higher inferior disc grade was associated with neurological deficit (7 events; OR per grade 1.93, 1.01-4.18) and less cement leakage (OR 0.59, 0.36-0.90). Conclusions Disc abnormality is frequent in SpineJack®-treated thoracolumbar fractures. The higher frequency in OVFs is largely explained by age. Associations with neurological deficit and cement leakage are exploratory. Fracture classification alone does not predict disc abnormality severity.