Symptoms of Grade 2 Anterolisthesis of L5 on S1
Grade 2 anterolisthesis of L5 on S1 typically presents with lower back pain, bilateral or unilateral leg pain (radiculopathy), neurogenic claudication, muscle weakness in the lower extremities, and sensory changes including paresthesias in the legs and feet. 1, 2
Primary Clinical Manifestations
Pain Patterns
- Lower back pain is the most common presenting symptom, often described as constant and worsening with activity 3
- Radicular pain radiating to the posterior thigh, leg, or foot occurs when nerve root compression is present 2, 4
- Pain typically worsens with standing, walking, or lumbar extension and may improve with sitting or forward flexion 1
Neurological Symptoms
- Bilateral lower extremity symptoms are common due to central canal stenosis at the L5-S1 level 1, 3
- Muscle weakness in the lower extremities, particularly affecting foot dorsiflexion or plantarflexion depending on nerve root involvement 4
- Sensory deficits including numbness, tingling, or paresthesias in dermatomal distributions 2, 3
- Positive straight leg raise test may be present when nerve root irritation occurs 1
Functional Limitations
- Neurogenic claudication manifesting as leg pain, weakness, or heaviness with walking that improves with rest 5, 2
- Difficulty with prolonged standing or walking, requiring frequent rest breaks 3
- Altered gait patterns due to pain, weakness, or instability 3
- Challenges with daily activities involving hip movement, sitting, or maintaining stable posture 3
Severity Indicators
Grade 2 Specific Features
Grade 2 anterolisthesis (25-50% vertebral body slippage) 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
- Higher risk of spinal canal stenosis from the degree of vertebral displacement 1
- Greater functional impairment compared to lower grade slippages 1
Red Flag Symptoms
Cauda Equina Syndrome (Rare but Critical)
While uncommon in grade 2 anterolisthesis, watch for 6:
- Bladder or bowel dysfunction (urinary retention, incontinence)
- Saddle anesthesia (numbness in the perineal region)
- Bilateral severe lower extremity weakness
- Progressive neurological deficits
These symptoms require urgent MRI evaluation and immediate surgical consultation 6.
Associated Findings
Musculoskeletal Manifestations
- Muscle tightness in the lumbar paraspinal muscles, hamstrings, and hip flexors 3
- Piriformis syndrome may coexist, exacerbating sciatic nerve compression 3
- Reduced lumbar range of motion, particularly with extension 3
- Postural changes to compensate for pain and instability 3
Clinical Pitfalls
Common diagnostic errors to avoid:
- Not correlating imaging findings with clinical symptoms—disc abnormalities are common in asymptomatic patients, so symptoms must match the anatomical level 6
- Overlooking dynamic instability—static radiographs may underestimate the degree of slippage; flexion-extension views are essential 2
- Missing coexisting pathology such as synovial cysts, facet arthropathy, or adjacent level stenosis that contribute to symptoms 1, 5
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. 6, 2