Spondylolisthesis is a forward or backward slip of one vertebra relative to the one below. It can cause back pain and pain radiating to the legs; treatment is planned according to the degree of slip and the symptoms.
What is spondylolisthesis?
Spondylolisthesis is the displacement of one vertebral body relative to the vertebra below. In the lower back it most commonly occurs at the L4-L5 and L5-S1 levels. The main types are:
- Degenerative spondylolisthesis: Caused by wear of the discs and joints in older age; especially common in women and at the L4-L5 level. It is often accompanied by spinal stenosis.
- Isthmic spondylolisthesis: Develops from a crack or defect (spondylolysis) in the part of the vertebra called the pars interarticularis; it can also occur in young people and athletes.
- Slips due to trauma, congenital and other causes
The grade of slip is classified according to how far one vertebra has moved relative to the other.
Symptoms
- Lower back pain, especially worse with standing and walking
- Pain and numbness spreading to the buttocks and legs
- Leg fatigue when walking (with associated stenosis)
- Tightness of the hamstring muscles
Diagnosis
Standing X-rays and flexion-extension X-rays show the degree of slip and whether it is mobile (unstable). MRI shows nerve compression, and CT evaluates the pars defect and bony anatomy in detail.
Treatment Approach
Most low-grade slips are managed successfully without surgery: medication, physiotherapy, exercises to strengthen the abdominal and back muscles, weight control and, in suitable patients, interventional pain treatments.
Surgery is considered for pain that does not respond to non-surgical treatment, progressive slip, or weakness due to nerve compression. The operation relieves pressure on the nerves (decompression) and stabilises the slipped vertebrae with screws and rods so that they fuse (fusion).