What is spondylolisthesis?
Spondylolisthesis is a condition in which one vertebra slips forward over the vertebra below it. The term comes from the Greek words for vertebra and sliding. It can occur at any level of the spine but is most common in the lumbar region at L4-L5 and L5-S1.
The severity is graded from I to IV based on the percentage of slippage. Grade I and II slips are the most common and can often be managed conservatively. Grade III and IV slips — where the vertebra has moved more than 50% of its width — typically require surgical stabilization.
Dr. Enguidanos is a fellowship-trained spine surgeon treating spondylolisthesis at HCA Florida Twin Cities Hospital in Niceville, Florida. He evaluates every patient individually to determine whether the slip is stable or progressive, and whether conservative care or surgery is the appropriate treatment.
Common symptoms.
- Low back pain that is worse with standing, walking, or extending the spine
- Pain that improves with sitting or flexing forward
- Radiating pain, numbness, or tingling into the buttocks and legs
- Leg weakness or heaviness with walking — neurogenic claudication
- Tight hamstrings — a compensatory response to the pelvic tilt from spondylolisthesis
- A visible step-off deformity in the lower back in high-grade slips
- Loss of lumbar lordosis — the lower back appears flat
- Bowel or bladder symptoms in high-grade or acute slips — requires urgent evaluation
What causes it.
- Isthmic — a stress fracture in the pars interarticularis, common in young athletes
- Degenerative — facet joint and disc degeneration allowing progressive slippage in adults
- Congenital — abnormal vertebral formation increasing susceptibility to slippage
- Traumatic — acute fracture allowing vertebral displacement
- Pathological — bone disease or tumor weakening the posterior elements
- Post-surgical — disruption of posterior stabilizing structures during prior surgery
When to call us.
Seek evaluation when back pain is accompanied by leg symptoms, when symptoms are progressive despite conservative treatment, when imaging shows a Grade II or higher slip, or when neurological symptoms — weakness, numbness, or bowel and bladder changes — are present.
Not all spondylolisthesis requires surgery. A Grade I stable degenerative slip in an otherwise healthy adult may be managed with physical therapy, core strengthening, and activity modification for years. The decision to operate is based on symptom severity, slip grade, and whether the slip is stable or progressing.