Spinal phenotypes on MRI and X-ray alone cannot predict short-term progression of lumbar disc degeneration.

INTRODUCTION

Different lumbar phenotypes impact the biomechanical properties and might lead to progressive degeneration of the spine. This study aims to investigate whether lumbar phenotypes observed through X-rays and MRIs can predict the progression of intervertebral disc degeneration (IVDD).

METHODS

A retrospective longitudinal cohort study was conducted to identify important variables for the progression of intervertebral disc degeneration (IVDD). The study included n = 279 patients (n = 1395 discs), who respectively underwent two lumbar magnetic resonance imaging (MRI) exams with an interval between 1 and 4 years. The Pfirrmann grade was allocated to score IVDD. Lateral standing X-rays evaluated sacral slope, lumbar lordosis, spondylolisthesis, and osteophytes. Anteroposterior X-rays examined lumbar scoliosis and pelvic obliquity. Sagittal MRI T2 imaging assessed muscle atrophy, intervertebral disc level (IVD), end plate defects, Modic changes, annular tears, disc protrusion, extrusion, sequestration, IVD height, and Pfirrmann grade. Axial T2 imaging evaluated facet joint angles. The study used correlation analysis and conditional logistic regression analysis to identify significant variables.

RESULTS

The likelihood to contribute to the progression IVDD was 100% for end plate defect. Protrusion follows closely at 88%, the female gender shows a likelihood of 72%, lower IVD level has a likelihood of 45%, the sacral slope is present at 40%, osteophytes have a possibility of 37%, suggesting they also play a role in the progression of IVDD. Weak positive correlations with IVDD progression are noted: r =.056 (sacral slope), 0.146 (disc level), 0.057 (osteophytes), 0.066 (end plate defect), 0.130 (protrusion), and 0.068 (sequesters).

CONCLUSION

Lumbar phenotypes like sacral slope, disc level, osteophytes, end plate defect, and protrusion were the most predictive phenotypes for IVDD progression. Relying solely on lumbar phenotypes may not provide, however, enough specificity and sensitivity for predicting IVDD progression.