Traumatic lateral lumbosacral dislocation: one case and review of literature. 
Lateral traumatic lumbosacral dislocation is a rare and severe lesion of the lumbosacral junction.  Only one case has been reported in the literature.  We report a new case of pure lateral lumbosacral dislocation.  A 27-year-old man had an isolated pure lateral traumatic dislocation of the lumbosacral junction after a motorcycle accident.  The diagnosis and the therapeutic course are analyzed and discussed.  Traumatic lumbosacral dislocation usually occurs in patient with multiple traumas.  Generally, in the case of complete fracture-dislocation, on lateral radiographs one can observe the L5 vertebra slippage over the sacrum, resulting from an associated severe disc disruption.  This feature was not seen in our patient.  Surgical treatment consisted of an open reduction of the dislocation, stabilization with posterior instrumentation, and a lumbosacral arthrodesis by posterolateral grafting.  In cases of pure lateral dislocation, short instrumentation can be recommended, extending from L5 to S1.  Addition of an interbody fusion should be considered when the L5-S1 disc is disrupted, which is responsible for the anterior slippage of L5 over S1.  Disc disruption can be evoked on preoperative magnetic resonance imaging (MRI) and intraoperatively by exploring the spinal canal.  Pure lumbosacral dislocation with a lateral translation seemed to have no disc disruption as observed in complete fracture dislocation.  Nevertheless, we recommend looking for an L5-S1 disc disruption either on preoperative MRI or during surgical exploration.