Spondylolisthesis is the displacement of one vertebra over another and is numbered up to 5 grades depending on the distance it has moved.
When the vertebra is displaced forward, it is called anterolisthesis and backwards, retrolisthesis. If it slides too far, the bone can trap the spinal cord or nerves.
It can be unstable and cause canal stenosis and/or low back pain with movement or standing. It occurs more frequently in lumbar segments, especially in the latter (L4-L5-S1). Although it can also occur at the cervical level.
Most of the symptoms are the result of the associated lateral recess stenosis. Lateral recess stenosis refers to the narrowing which reduces the available space within the exit doorway (foramen) of the spinal canal.
Surgical treatment of degenerative lumbar spondylolisthesis
Degenerative lumbar spondylolisthesis requires surgical intervention in only a minority (10-15%) of patients.
Decompression is a surgical procedure done to relieve pain caused by pinched nerves (neural impingement). Thus, decompression alone has been the primary goal of surgery.
Recent studies have demonstrated improved outcomes with the addition of an intertransverse fusion. However, an improvement in patient outcome has not been demonstrated with instrumented fusions. Instrumented fusion should be reserved for patients at high risk for a progressive deformity such as:
- Patients with excessive motion on preoperative radiographs.
- A documented progressive slip.
- Those requiring a discectomy or total facetectomy to adequately decompress the neural elements.
This surgical procedure consists of the removal of the intervertebral disc (located between the vertebrae), then a bone graft or interbody fusion device is placed in that area. An interbody fusion may be advantageous in the following cases:
- When there is severe disc space collapse with narrowing of the neuroforamen.
- When a discectomy is performed as part of the decompression.
- To correct a kyphosis at that motion segment.
If the technique of the interbody fusion involves near-total or total facetectomy (removing a portion of one or more vertebrae) to allow for enough room to insert the interbody fusion device without injuring the nerve roots, the stability of the spine is affected and our specialists will recommend supplemental posterior instrumentation.
You might also want to read: Instrumented Lumbar Fusion for Degenerative Spondylolisthesis
At the London Spine Unit, we have some of the most qualified surgeons to perform degenerative spondylolisthesis surgery. Book an appointment to get a checkup.