Association between vertebral endplate lesions and sagittal spinal alignment: a retrospective imaging analysis in a selected adult patient population

Objective: Most endplate lesions are asymptomatic and incidentally detected. Prevalence in adults ranges from 28% to 46%, but their clinical relevance remains unclear. A knowledge gap persists regarding how spinal alignment parameters affect the type and distribution of lesions across lumbar levels. This study aims to bridge the gap by examining associations between alignment variables and lesion indices. Materials and methods: A retrospective study was conducted on 584 adults who underwent spine magnetic resonance imaging (MRI) and standing radiographs within 6 months, with at least one spinal level exhibiting an endplate lesion between T12-L1 and L5-S1. Lesions were graded using a validated MRI-based classification system (normal, wavy/irregular, notched, Schmorl nodes). Modic changes, sagittal alignment parameters, and lumbopelvic profile (Roussouly classification) were also evaluated. Associations between demographic and alignment variables with lesion indices were analyzed through correlation and regression models. Results: Endplate lesions were found in 60% of spinal levels (30% wavy/irregular, 20% notched, 10% Schmorl nodes). Modic changes were absent in 84% of levels, yet 53% of these displayed lesions. Lesion severity increased with age and was slightly higher in males. Reduced lumbar lordosis correlated inversely with lesion indices, indicating a higher prevalence in flatter alignments. Severe lesions were somewhat more common in upper lumbar levels. Lumbopelvic profiles 1 and 2 showed higher lesion prevalence and severity, though profile type was not an independent predictor. Conclusion: Endplate lesions increase with age and reduced lumbar lordosis. While sagittal parameters and lumbopelvic profiles modulate lesion distribution, their predictive power is limited, supporting a multifactorial etiology of endplate degeneration. Relevant statement: Endplate lesions increase with age and reduced lumbar lordosis. Although sagittal alignment and lumbopelvic profiles influence their distribution, these parameters show limited predictive value, highlighting the multifactorial nature of endplate degeneration and the need for integrated morphological and biomechanical assessment in spinal evaluation. Key points: Endplate lesions prevalence and severity increase with age, occur slightly more in upper lumbar levels, and show a weak-to-moderate Modic changes association. Reduced lumbar lordosis could predispose to endplate lesions, suggesting unfavorable load transfer across spinal segments. Lumbopelvic profile influences lesion distribution but is not an independent predictor of lesion presence or type.