Introduction. Low back pain and disc degeneration could be linked to global spinal
geometry. Our study aimed to develop a reliable new mathematical method to assess
the local distribution of total lumbar lordosis with a single numeric parameter and
compare it with lumbar intervertebral disc degeneration using routine MRI scans. Methods.
An online, open access, easy-to-use platform for measurements was developed based
on a novel mathematical approach using MRIs of 60 patients. Our Spinalyze Software
can be used online with uploaded MRIs. Several new parameters were introduced and
assessed to describe variation in segmental lordosis distribution with a single numerical
value. The Pfirrmann grading system was used for the classification of lumbar intervertebral
disc degeneration. Relationships were investigated between the grade categories of
L1-S1 lumbar discs and the MRI morphological parameters with correlation analysis.
Results. Results confirm that the determination of measurement points and calculated
parameters are reliable (ICCs and Pearson r values > 0.90), and these parameters were
independent of gender. The digression percentage (K%), one of our new parameters,
did not show a statistical relationship with the Cobb-angle. According to our results,
the maximum deflection breaking-point of lumbar lordosis and its location can be different
with the same Cobb-angle and the distribution of global lordosis is uneven because
the shape of the lumbar lordosis is shifted downward and centered around the L4 lumbar
vertebra. The interobserver reliability of the Pfirrmann grades reading was in the
excellent agreement category (88.33% agreement percentage, 0.84 kappa), and digression
percentage (K%) showed a significant negative correlation with all L1-S1 disc grades
with increasing r correlation values. This means that the smaller the value of digression
percentage (K%), the more the number of worn discs in the lower lumbar sections. Conclusions.
Spinalyze Software based on a novel mathematical approach provides a free, easy-to-use,
reliable, and online measurement tool using standard MRIs to approximate the curvature
of lumbar lordosis. The new reliable K% (digression percentage) is one single quantitative
parameter to assess the local distribution of total lumbar lordosis. The results indicate
that digression percentage (K%) may possibly be associated with the development of
lumbar intervertebral disc degeneration. Further evaluation is needed to assess its
behavior and advantage.
