Spondylolisthesis

Spondylolisthesis is forward slippage of one vertebra over the one below it. The two most common causes are degenerative — wear and tear on the disc and facet joints that lets the bones slide — and isthmic, from a small stress fracture in the back of the bone that allows the slip.

The slippage itself often isn't the main problem. The narrowing of the spinal canal and nerve openings that comes with the slip is what produces symptoms: low back pain and, frequently, leg pain or weakness that mimics spinal stenosis.

X-rays in standing and flexion-extension positions are essential — they show the slip and whether it moves with motion. MRI shows what the nerves are doing.

Most patients benefit from a conservative approach first: physical therapy, anti-inflammatories, and an epidural injection if there is significant leg symptom. Many do well long-term without ever needing surgery.

When surgery is needed, the decision is usually decompression alone versus decompression with fusion. For grade-I stable slips and modest symptoms, decompression alone can be enough. For larger slips, mobile slips, or significant back pain that mirrors the affected level, fusion is the more reliable answer.

Surgery is considered for significant leg pain or weakness unresponsive to conservative care, for documented progression of the slip, or for severe mechanical back pain that limits your function.

For patients who need it, a TLIF or PLIF at the affected level decompresses the nerves and stabilizes the segment in one operation. Recovery is meaningful — one to two nights in the hospital, several weeks of activity restriction — but the outcomes are durable.