Spinopelvic Parameters among Healthy Volunteers in Iran

Background: Recently, in approach to spinal pathologies, the whole spine should be considered as a biomechanical unit. Studies have shown the great importance of sagittal and coronal balance and the relationship between the various parts of spine together and pelvis. Former studies have shown a close relationship between spinopelvic parameters and sagittal balance. A complete understanding of sagittal balance basics is needed to achieve the best outcome and avoiding future complications after treatment of spinal deformities. In this study, the normal range of spinopelvic parameters among healthy volunteers in Iran has been evaluated. Methods: This cross-sectional study was conducted on healthy volunteers in 2017. The lateral whole-spine X-ray was obtained under the standard conditions. Two spine surgeons measured the parameters including pelvic incidence, pelvic tilt, sacral slope and lumbar lordosis. Results: In this study 100 volunteers were studied; out of whom, 41 participants were male and the mean age was 47.5±11.7 years. The average pelvic incidence, pelvic tilt, and sacral slope were 51.5±10.9, 17.4±9.9, and 34.8±8.8 degrees, respectively. The pelvic tilt was significantly lower in women. It was found that with increasing age, the pelvic incidence and pelvic tilt increases while lumbar lordosis decreases (P<0.05). Conclusion: This study is the first study on the normal range of spinopelvic parameters in healthy individuals in Iran.. Our data showed that PT and PI-LL are significantly lower in women, while, PT, PI and PI-LL increase and LL decreases in older ages.