Bilateral spondylolysis of inferior articular processes of the fourth lumbar vertebra: a case report

Lumbar spondylolysis, a well known cause of low back pain, usually affects the pars interarticularis of a lower lumbar vertebra and rarely involves the articular processes. We report a rare case of bilateral spondylolysis of inferior articular processes of L4 vertebra that caused spinal canal stenosis with a significant segmental instability at L4/5 and scoliosis. A 31-year-old male who had suffered from low back pain since he was a teenager presented with numbness of the right lower leg and scoliosis. Plain X-rays revealed bilateral spondylolysis of inferior articular processes of L4, anterolisthesis of the L4 vertebral body, and right lateral wedging of the L4/5 disc with compensatory scoliosis in the cephalad portion of the spine. MR images revealed spinal canal stenosis at the L4/5 disc level. Posterior lumbar interbody fusion of the L4/5 was performed, and his symptoms were relieved.