Exploring spinal geometry: The significance of Cobb’s and Ferguson’s angles in low back pain patients

Introduction: The vertebral column consists of vertebrae connected by interbody joints, facet joints, ligaments, and muscles. Evolutionarily lumbosacral angle appears to have developed with erect posture and bipedal locomotion. Lumbar Lordosis (LL) is the curvature of the lumbar spine, measured by Cobb’s method, measured between L1 cranial endplate and S1 cranial endplate. Lumbosacral angle/Ferguson’s angle, is the angle between the plane of the superior margin of S1 vertebrae and a horizontal line. This study aimed to measure Cobb’s Angle and Ferguson’s Angle on MRI Images (T2w) in patients with low back pain. Materials and Methods: In the present study, MRI images (T2w) of total 210 patients (92 males & 118 females) suffering with low back pain were taken via Autocad software and measurements of Cobb’s and Ferguson’s angles were taken. Results: Of the total samples, mean Cobb’s angle was 44.60° ± 11.390° and mean Ferguson’s angle was 37.63° ± 8.027°, showing a statistically significant strong positive correlation (r = 0.925, p <0.001). Both males and females had significant positive correlations between Cobb’s and Ferguson’s angles (p <0.001 in both and r = 0.927 in males and r = 0.931 in females). In males, there was a statistically significant correlation between Likert pain scale and both Cobb’s angle (p = 0.008) and Ferguson’s angle (p = 0.005), in females only Cobb’s angle correlated with pain (p = 0.019). Conclusions: This study concluded that with increasing pain both the Cobb’s and Ferguson’s angles increase. Both angles also tend to increase with advancing age. Measurement of these angles will be helpful in targeted assessment and interventional strategies for low back pain. Keywords: Cobb’s angle, Ferguson’s angle, Low back pain, Lumbosacral angle