Spondylolisthesis may be defined as the slippage of one vertebra upon another, to a varying degree, with consequent compression of the spinal cord and of the nerve roots arising from it. It is among the common causes of back and leg pain.
Overview
The term spondylolisthesis derives from the Greek spondylos, meaning vertebra, and olisthesis, meaning slippage.
The condition has five subtypes:
- isthmic;
- degenerative;
- traumatic;
- dysplastic;
- pathological.
Symptoms
Many patients with spondylolisthesis have no symptoms at all. Various findings may nonetheless arise from the instability at the level of the slippage.
Abnormal movement at that level may cause back pain. The pain typically increases with activities such as standing and walking and eases with rest.
Some patients have leg pain (sciatica, radiculopathy) together with weakness and/or numbness arising from damage to the nerve roots compressed by the slippage.
In adult patients the slippage may give rise to the degenerative changes known as spinal spondylosis: disc herniation, hypertrophy of the ligaments, overgrowth of the facet joints and bony spurs. These changes narrow the spinal canal and may lead to spinal stenosis and neurogenic claudication.
Diagnosis
- Plain Radiographs
- Allow assessment of whether slippage is present, and of kyphosis, scoliosis and spinal balance. Bony pathology such as spurs, narrowing of the disc space and vertebral fracture may also be identified.
- Dynamic Radiographs
- Flexion and extension views — radiographs showing the spine in movement — may be obtained to determine whether there is abnormal or excessive movement, or instability, at the affected levels.
- Magnetic Resonance Imaging (MRI)
- Provides detailed images of the soft tissues, including the spinal cord and the nerve roots. It helps to establish the site and severity of the narrowing and to identify compression of the spinal cord or a nerve root.
- Computed Tomography (CT)
- Used for a more detailed assessment of the bony structures.
Treatment
In many patients, non-operative measures are recommended as the first treatment.
- medication;
- physiotherapy — the back, flank and abdominal muscles are strengthened in order to provide dynamic support to the lower lumbar spine;
- weight loss and changes to lifestyle.
Surgery is undertaken in patients with severe and progressive back and/or leg pain that cannot be relieved by conservative means such as physiotherapy, medication and modification of activity, and in patients with a neurological deficit.
Surgery
The purpose of the operation is to relieve the pressure on the nerve root. Laminectomy and fusion are performed.
The level at which the slippage has occurred and the adjacent vertebrae are stabilized with a screw–rod construct, and the compressed nerve roots are released.