Abstract

Introduction: Lumbosacral transitional vertebra (LSTV) is one of recognized morphological variant associated with back pain. As sacrum has very crucial role in weight transmission via sacroiliac joint, any change in morphology of auricular surface of sacrum should have impact in morphology of lumbosacral region. Aim: To study relation between the variable extent of auricular surface in Sacrum and prevalence of Lumbosacral Transitional Vertebra (LSTV) along with changes in morphological index. Materials and Methods: Present study was done by taking total 40 adult dry human sacra of both sexes which were collected from the Department of Anatomy at Himalayan Institute of Medical Sciences, SRHU, Dehradun. All sacra were initially divided into two sacral groups of normal sacra and atypical sacra based on absence and presence of any type of lumbosacral transitional vertebra (LSTV) respectively. Further each group subcategorized into three, namely A (normal sacra), B (high sacra) and C (low sacra) based on extend of auricular surface. Metric traits like maximum auricular length, maximum sacral length, maximum sacral width and sacral index were measured and compared. Result: In this study sacra with higher type of auricular surface were found to be associated with more incidence of sacralization whereas sacra with lower type of auricular surface were associated with lumbarization. There was significant difference noticed in mean sacral index of these two sacral groups. Sacral index in sacral group with LSTV (Mean 95.06) was found to be less on comparing with sacral group without LSTV (Mean 108.20). Increased mean maximum sacral length (mean 109.62) seen in sacral group with LSTV without significant change in maximum sacral width (mean 103.75) which can be due to shift of weight transmission axis from lower sacral vertebrae to higher vertebrae. Conclusion: Variable extents of auricular surface of sacrum are associated with variant of lumbosacral transition vertebra due to change in biomechanics of weight transmission. Thus this study may be helpful to clinicians to predict and treat root cause of LSTV associated back pain.

Authors and Affiliations