Traumatic spondylolisthesis of L5-S1

Pure traumatic bilateral lumbosacral dislocation is a rare injury with just eight cases reported in the literature. This condition occurred also in 36-year-old man, who was struck into the lower back by a falling tree, during a woodcutting, at the moment when he was kneeling and his spine was flexed. Neurological examination showed no signs of spinal nerves injury. X-ray examination of the lumbosacral spine revealed the presence of a 40% anterior dislocation of L5 over S1 with locked facets and multiple fractures of transverse processes. Computer tomography confirmed these findings and also revealed massive medial L5-S1 disc herniation. Surgery performed 9 days after the injury consisted of L5 laminectomy, L5-S1 discectomy and segmental reduction and stabilization with transpedicular screws. Posterior lumbar interbody fusion was carried out using titanium PLIF-blocks. The patient healed without complications. At a 24-month follow-up he was without any subjective complaints, neurologically asymptomatic and without restriction of mobility in the lumbosacral spine. He was able to resume his previous work. This rare case is discussed in a view of the relevant literature, biomechanics of trauma and the appropriate therapy with an emphasis on open reduction and internal fixation techniques.