Degenerative Spondylolisthesis of Lumbarized S1-S2 Vertebrae: A Case Report

Introduction Degenerative spondylolisthesis (DS) is usually seen at lumbo-sacral region. Lumbarization of S1 is seen in less than 2% of the population and to have spondylolisthesis in this segment is even rarer. The purpose is to report a rare case of DS at S1-S2 level. Case Report A 52-year-old male, a farmer by profession, presented to Neurosurgery outpatient department with complaint of low back ache for 4 years, which was insidious and progressive. The pain radiated to both lower limbs with more on right than left side. Radiological evaluation with anteroposterior and lateral roentgenogram of lumbo-sacral spine revealed anterolisthesis of S1-S2 (Meyerding's grade 2). Magnetic resonance imaging reported S1-S2 disk bulge with bilateral foraminal stenosis. The patient underwent S1 laminectomy along with S1-S2 discectomy with bilateral S1 and S2 pedicle screws and rod fixation with transforaminal lumbar interbody fusion. Result Postoperative recovery was good with improvement in back pain along with power on postoperative day 1. Conclusion The prevalence of lumbarization is less than 2% and getting spondylolisthesis in this segment is even rarer. As this is one of the first of its kind of case, further case series or longitudinal studies of such cases may help understand better the pathomechanics related to spondylolisthesis at this level.