Spondylolisthesis
Spondylolisthesis means one vertebra has slipped forward on the one below it. Many slips are stable and cause little trouble. Others narrow the space for the nerves or move with activity, producing back pain and leg symptoms. Understanding which kind you have determines the treatment.
How a vertebra slips
In isthmic spondylolisthesis, a small stress fracture in the back of the vertebra, usually acquired in adolescence, allows the vertebra to drift forward over the years. It is most common at the lowest level of the spine (L5 on S1). In degenerative spondylolisthesis, wear of the facet joints in later life allows the slip, most often one level higher (L4 on L5). Degenerative slips are more common in women and are frequently found together with spinal stenosis.
Slips are graded by how far the vertebra has moved. Low-grade slips are the norm; high-grade slips are uncommon and are managed differently.
Symptoms and evaluation
Back pain that worsens with standing and arching backward is typical, along with leg pain or heaviness when walking if the slip has narrowed the canal or the nerve openings. Standing X-rays, including bending views, are the key test because they show whether the slip moves with position. An MRI shows the effect on the nerves.
Treatment
Most patients are treated without surgery. Physical therapy focused on core stabilization and hamstring flexibility, activity modification, and anti-inflammatory medication help most. Epidural steroid injections are useful for leg symptoms.
Surgery is considered when leg symptoms or back pain remain disabling despite good nonsurgical care, when the slip is progressing, or when there are neurologic changes. Because a slipped segment is unstable by definition, a decompression alone risks making the slip worse, so the standard operation is a decompression combined with a fusion of the slipped level. Dr. Michael performs this most often as a minimally invasive TLIF, using navigation or robotic guidance for screw placement, which allows the same operation through smaller incisions with less muscle disruption. The slipped vertebra is typically realigned as much as is safe, and the segment is stabilized while the bone heals.
Common questions
Is a slipped vertebra dangerous?
Low-grade slips are common and usually not dangerous. They deserve monitoring and treatment when they cause symptoms. High-grade or progressing slips warrant a surgeon's evaluation.
Can spondylolisthesis be fixed without a fusion?
For a stable slip causing leg symptoms, a decompression alone is occasionally appropriate, but in most cases the segment needs to be stabilized, and a fusion is the reliable way to do that.
How long is recovery after a fusion for spondylolisthesis?
With a minimally invasive TLIF, most patients go home in one to two days, walk immediately, and return to light activity within a few weeks. The fusion itself matures over six to twelve months, and heavier activities are added progressively during that time.