This patient is a 66 year-old gentleman who previously had an L5-S1 instrumented fusion in 2007 (by me) for severe back pain and bilateral lower extremity pain. This pain was caused by an isthmic spondylolisthesis, a spinal condition in which one vertebra slips forward over the vertebra below, at L5/S1.
His symptoms were resolved after surgery but then in 2016 he developed recurrent back pain, leg pain, and foot numbness. His imaging showed that he had progressive spondylosis (degenerative changes) of the lumbar spine and adjacent level disease (from the prior fusion). He had significant spondylolisthesis at L4/5 and scoliosis in the lumbar spine.