Sacralization and Herniated Nucleus Pulposus -An Association Study

Abstract

Introduction: Herniated nucleus pulposus (HNP) can be best diagnosed clinically by history followed by physical examinations suggested by Mckenzie and Cyriax as well as radiologically by MRI. Sacralization, which is mostly congenital in origin in later life, gives rise to altered biomechanics. It is thought to be a leading cause of low back pain and HNP. There is controversy in the literature whether sacralization is associated with HNP or not. So the present study intended to find out whether sacralization is associated with HNP. Methodology: A total no of 150 subjects with LBP with or without radiation to lower limb were taken in the study. MRI report from each subject was studied. Subjects were diagnosed as HNP when they fulfill the clinical criteria as well as the MRI suggesting HNP. Sacralization was diagnosed by using lumbo-sacral A-P radiograph and various types of sacralization were noted. Pain was measured by using VAS, A-P diameter of spinal canal is noted from MRI and disability status was measured using ODI and WHODAS-2 (12 items). Results: Result of the study showed that 71.42% sacralized subjects have HNP and sacralized subjects are 5.92 times risk for HNP, the relative risk factor for HNP in type 2 a and 1b is highest i.e., 9.44 each , next to it is type – 4 i.e., 7.08. The prevalence of LSTV was found to be 44% which includes sacralization (42%) and lumbarisation (2%). It has been found that incidence of sacralization in HNP group also found to be more i.e., 64.28 %. Besides this, it has also been found that sacralized subjects suffer from more disability and there is a weak correlation between SLR and disability. However, sacralization doesn’t give rise to significant reduction of A-P diameter of spinal canal and more pain. Conclusion: Sacralization is a risk factor for HNP and out of all sacralization type – 1B and 2A risk factor is highest. It has also been found that prevalence of sacralization in the low back pain population is more, sacralized individual suffered from more disability but not more pain or any changes in A-P diameter of spinal canal. SLR is weakly correlated with disability, A-P diameter of spinal canal and pain are not correlated.