PMC

Our patient had a similar mechanism of injury as a motor vehicle accident with head-on collision. The points of fixation by seatbelts are replaced by body weights and the momentum of the body is replaced by a fulcrum at the metal bar. Both situations result in a forward motion of the lumbar spine relative to the remainder of the body with hyperextension of the lumbar spine

a Collision site of metal bar as fulcrum. b XR showing grade II spondylolisthesis of L4 on L5, fracture dislocation of facet joints, and fractures of left transverse processes from L1 through L4, a fracture of posterior inferior L4 vertebral body, spina bifida occulta of L5. c, d. CT scan showing fracture of bilateral L4 inferior articular processes, fracture of left L4 transverese process, left L4 pedicle and the L4 spinous process, L4 vertebral body fragment retropulsion causing severe spinal canal narrowing, and coronally oriented L4/5 facets. e Spontaneous reduction of dislocation upon prone position. f Laminectomy and posterior spinal fusion with instrumentation. g Post-operative XR showing reduction of dislocation