An Automatic Method for Measuring Lumbar Lordosis Angle

Natural curves of the spinal column adjust the head to line up with the hip. They also control the absorption of sudden shocks and mechanical forces. The investigation of the angle of lumbar lordosis is widely used in lumbosacral pathological studies. This study aimed to improve the accuracy and speed of measuring lumbar lordosis angle. This cross-sectional analytic study was conducted in Isfahan University of Medical Sciences, Iran during 2010. One hundred patients (50 men and 50 women) with low back pain and available lateral lumbar radiographs and their corresponding electronic files were recruited from the Kashani Hospital (Isfahan, Iran). The angle of lumbar lordosis on lateral lumbar radiographs was measured twice using our suggested image processing method and conventional non-automatic method (based on Cobb's principle). The obtained data was analyzed using descriptive statistics, paired t-test and Pearson's correlation test. The mean age of patients was 44 ± 8 years. The mean lumbar lordosis angle was calculated as 35.0 ± 8.1 degrees using conventional non-automatic method and as 37.0 ± 7.6 degrees using our image processing method. The mean angles of lumbar lordosis measured in these methods were significantly correlated (r = 0.89; P < 0.05). Although measurement of lumbar lordosis angle is commonly performed based on the clinical method using flexible rulers or conventional non-automatic method using radiographs, our automatic image processing method was also a reliable tool to measure lumbar lordosis angle more quickly and accurately.