Pelvic parameters in patients with chronic low back pain and an active disc disease: A case-control study

Introduction/Background Active disc disease is characterized by inflammatory-like low back pain (LBP) and the presence of Modic 1 changes on MRI. Its prevalence ranges from 19% to 50% in patients with nonspecific chronic LBP. Pelvic parameters are important determinants of shear and compressive forces applied to the lumbar intervertebral disc. The association between an active disc disease and abnormal pelvic parameters has not been addressed yet. We aimed to compare pelvic parameters between chronic LBP patients with an active disc disease (Modic 1) and those without (Modic 0). Material and method We used a convenient sample from patients prospectively and consecutively recruited in a previous single center case-control pilot study. Cases were defined as chronic LBP male patients with an active disc disease on MRI and controls as patients without. Pelvic parameters, namely sacral slope, pelvic tilt and pelvic incidence, were assessed in an independent and standardized manner by two trained investigators using EOS system imaging performed at inclusion. Results Overall, 35 cLBP patients (13 cases and 22 controls) fulfilled inclusion criteria and had an EOS imaging available. Median age was 42 (35–51.5) years and median LBP duration 50 (33.5–104) months. Pelvic parameters did not differ between the 2 groups: absolute mean (95% IC) difference between Modic 0 and Modic 1 was −7.2° (−15.5; 1.0) for pelvic incidence, −3.7° (−8.7; 1.3) for pelvic tilt and −3.3 (−8.9; 2.3) for sacral slope. Conclusion Pelvic parameters in patients with chronic LBP and an active disc disease do not differ from those in patients without.