Findings:
Anterior displacement of L4 in relation to L5, Grade I anterolisthesis with evidence of defect in pars interarticularis at this level.
Minimal posterolisthesis is also noted at L5/S1.
High grade intervertebral osteochondrosis at L4/5 with irregularities and subchondral sclerosis involving the endplates, marginal osteophytes, and disc degeneration with gas. Also broad-based total disc and bilateral osteoarthritis of the facet joints is seen at this level with moderate bilateral neural exit foraminal stenosis at L4/5.
Mild disc bulging is also noted at L3/4 and L5/S1 without any relevant stenosis.
The imaged soft tissue is unremarkable.
Impression:
Grade 1 anterolisthesis L4/5 due to bilateral spondylolysis with prominent intervertebral osteochondrosis, pseudo-disc and osteoarthritis of the facet joints, suggestive of chronic instability.