Evaluation of Spinopelvic Parameters in Patients with Different Grades of Intervertebral Disc Degeneration in Lumbosacral Spine vs Normal Asymptomatic Population: A Retrospective Observational Study

Introduction: Spinopelvic malalignment causes continual backache. Intervertebral Disc Degeneration (IDD) is a leading cause of low backache. Understanding the relationship between spinopelvic parameters and IDD can help with better diagnosis and treatment and avoid unnecessary investigations.

Aim: To measure radiographic spinopelvic parameters of patients diagnosed with varying grades of IDD in the lumbosacral spine on Magnetic Resonance Imaging (MRI), and to compare them with radiographs of the asymptomatic population (controls).

Materials and Methods: A hospital-based retrospective observational study was done from January 2021 to August 2022 at a tertiary care hospital in Uttar Pradesh, India with 80 patients diagnosed with IDD on MRI and 80 controls. Cases were defined as patients diagnosed to have IDD on MRI and controls were those individuals who did not have disc degeneration on MRI. Lateral lumbosacral spine radiographs were taken, and spinopelvic parameters {Pelvic Tilt (PT), Sacral Slope (SS), Pelvic Incidence (PI), Lumbar Lordosis (LL), lumbo-sacral angle, and sacral horizontal angle} were measured using Surgimap Spine Software. T-test and Chi-square test were used for comparison between cases and controls.

Results: Six patients had asymmetric disc bulge, 11 had symmetric disc bulge, 18 had disc extrusion and 45 had disc protrusion. Mean PT in patients with IDD was 11.05±3.84°, and control was 8.65±3.19°, p-value=0.009. Mean SS in case group was 38.38±3.03° and control was 36.56±3.43°, p-value=0.031. The mean PI of cases was 49.44±8.39° and control 46.19±9.01°, p-value=0.02. LL angle was higher in IDD at 46.34°, and was 45.36° in healthy individuals, without statistically significant difference. The mean lumbo-sacral angle in both study groups was similar. The mean Sacral Inclination Angle (SIA) was found to be 43.99° and 44.96° in the case and control group respectively without showing significant differences. A statistically significant difference was found only for the comparison of PT between different grades of IDD (p-value=0.039).

Conclusion: Using Surgimap Spine Software, one can predict the individuals that possess a greater propensity of developing degeneration of disc and chronic low back pain in a more cost-effective manner.