What is spondylolisthesis?
The vertebrae are stacked and held in line by discs, joints, and ligaments. When that restraint weakens (through age-related change, or a defect in the bony bridge at the back of the vertebra), one bone can slide slightly forward on the one beneath it. The slip itself is often painless. Symptoms come from what the slip does to the canal and to the nerves passing through it.
Symptoms
- Low back pain that is worse standing and better sitting or lying down
- Leg pain, numbness, or tingling, often in both legs
- Walking tolerance that has decreased
- A sense of the back "catching" or giving way on changing position
- Tight hamstrings and a shortened stride in longer-standing cases
Urgent
Seek urgent care for new loss of bowel or bladder control, numbness in the saddle area, or rapidly worsening leg weakness.
How it is diagnosed
Standing X-rays show the slip and grade it. Flexion and extension views show whether the segment moves, which is the question that most affects treatment. MRI shows the nerves and the degree of crowding. As with stenosis, the examination determines how much weight the imaging carries.
Non-surgical treatment
Physical therapy focused on core and hip strength is the starting point, alongside activity modification and anti-inflammatory medication where appropriate. Injections may be used both to relieve symptoms and to help identify which level is responsible. Many people with a stable, low-grade slip are managed this way indefinitely.
When surgery is considered
Surgery is discussed when leg symptoms are limiting despite non-operative care, when weakness is progressing, or when the segment is demonstrably unstable. Decompression relieves pressure on the nerves; when the segment moves, a fusion may be added to stabilize it. Whether fusion is needed depends on the imaging and the examination, not on the presence of a slip alone.