Clinical Manifestations and Management of Grade 2 Anterolisthesis of L5 on S1

Primary Clinical Manifestations

Grade 2 anterolisthesis of L5 on S1 typically presents with lower back pain, bilateral or unilateral leg pain, neurogenic claudication, muscle weakness in the lower extremities, and sensory changes including paresthesias in the legs and feet 1, 2
Radicular pain radiating to the posterior thigh, leg, or foot occurs when nerve root compression is present 2
Pain typically worsens with standing, walking, or lumbar extension and may improve with sitting or forward flexion 1
Bilateral lower extremity symptoms are common due to central canal stenosis at the L5-S1 level 1
Sensory deficits including numbness, tingling, or paresthesias in dermatomal distributions 2
Positive straight leg raise test may be present when nerve root irritation occurs 1

Grade 2 anterolisthesis represents moderate instability and typically produces more significant symptoms than grade 1 1, 2
Increased likelihood of nerve root compression due to greater foraminal narrowing 2, 3
Higher risk of spinal canal stenosis from the degree of vertebral displacement 1
Greater functional impairment compared to lower grade slippages 1

Bladder or bowel dysfunction, saddle anesthesia, bilateral severe lower extremity weakness, and progressive neurological deficits are rare but critical symptoms that require urgent MRI evaluation and immediate surgical consultation 4
The American College of Radiology recommends urgent MRI evaluation for patients with cauda equina syndrome symptoms 4

Not correlating imaging findings with clinical symptoms is a common diagnostic error, as disc abnormalities are common in asymptomatic patients 4
Overlooking dynamic instability and missing coexisting pathology such as synovial cysts, facet arthropathy, or adjacent level stenosis can contribute to symptoms 1, 2, 3, 4
The presence of spondylolisthesis with neurological symptoms and functional impairment after 6 weeks of conservative management indicates the need for advanced imaging with MRI to assess nerve root compression and guide treatment decisions 2, 4