Open decompression for lumbar spinal stenosis running across several levels. The bone and thickened ligament crowding the nerves are removed level by level under direct view, so the nerves have room again. Where the spine is stable, nothing is fused — the operation makes space and leaves the anatomy otherwise intact.
Lumbar stenosis is a narrowing of the space the nerves occupy. It builds up slowly from several directions at once — the facet joints enlarge as they wear, the ligament along the back of the canal thickens and buckles inward, and the discs bulge from the front. The canal that was comfortably roomy becomes a tight ring around the nerves.
A laminectomy removes the back wall of that ring. The lamina and the thickened ligament are taken away over each narrowed level, and the recesses where the individual nerve roots turn to leave the spine are opened out. What is left is a canal with room in it.
The word to notice is multilevel. Stenosis at one level and stenosis at four are the same disease and quite different operations, and the number of levels is what moves this out of the tubular column and into the open one.
Lumbar central stenosis before and after decompression. Axial views at a stenotic level showing hypertrophied facets and buckled ligamentum flavum compressing the thecal sac, alongside the same level after laminectomy with the sac restored to a round profile.
The symptom that brings people in is neurogenic claudication, and it has a recognisable shape: the legs, not the back, are the problem, and posture changes everything.
The leaning-forward detail is diagnostic rather than incidental. Bending forward opens the canal a little, which is why a stenotic patient can push a shopping trolley much further than they can walk upright, and why a stationary bicycle is easier than a treadmill.
Dr. Zaidi performs most single and two-level decompressions through a tubular retractor, and for those it is an excellent operation: one small window, the muscle spread rather than stripped, and often the same day home.
That calculus changes as levels are added. A tube gives a superb view of a small area, so covering four levels means either several separate docking points or repeatedly angling from one — and by the time enough windows have been made, the access is no longer smaller than an open exposure, only more piecemeal. Severe circumferential stenosis, scarring from previous surgery and difficult anatomy all push the same way.
So the choice is not open versus minimally invasive as a philosophy. It is that the corridor should be as small as the work allows and no smaller — and past a certain amount of work, a direct view is the safer and more complete decompression. That reasoning is set out at length in how the approach is chosen.
This is the most consequential decision in stenosis surgery, and it is worth understanding before the consultation rather than during it. Removing the back of the canal relieves the nerves. It does not stabilise anything — and if enough of the joints has to come out to get the nerves free, it can leave a level looser than it was.
So the question at each level is whether that level is stable:
Adding a fusion is not the thorough version of this operation. Where the spine is stable, fusing it adds operating time, blood loss, implants and months of recovery without adding relief, and it transfers load to the levels next door. Where there is a slip, or where freeing the nerves means taking out the joints holding a level together, fusion is what makes the decompression safe — and then it is the right operation.
This is decided on standing and flexion-extension X-rays as well as the MRI, because a slip that only appears when the patient bends will not show on a scan taken lying down.
The patient is positioned face down on a frame that lets the abdomen hang free. That is not a comfort measure — pressure on the abdomen backs up the epidural veins and makes the operation bloodier.
A midline incision over the levels to be decompressed, and the muscle lifted off the laminae to either side. Imaging confirms the levels before any bone is removed.
The laminae are taken down across the stenotic levels and the thickened ligament beneath is removed from the sac. This is the step that gives the central canal its space back.
Each nerve root is followed out to where it leaves and freed at the lateral recess and foramen. Central decompression alone leaves the roots trapped at the shoulders — a common reason for persistent leg symptoms after surgery.
The facet joints are undercut rather than removed, so the nerves are freed while the joint capsules and enough of the joint remain to keep the segment stable. How much can be taken is the limit that decides whether a fusion is needed.
Every root is checked to be loose along its course, haemostasis is obtained, and the muscle and fascia are closed in layers over the decompressed canal.
Multilevel lumbar decompression. Laminae removed across several levels, ligamentum flavum lifted off the thecal sac, and each root followed out through an undercut facet into an opened lateral recess.
A decompression is an operation for leg symptoms. It gives the nerves room, so the walking distance, the heaviness and the leg pain are what respond, and they often respond quickly.
Figures are general ranges from the surgical literature, not guarantees for any individual case. Recovery varies with the number of levels decompressed, age, general health and what the nerves looked like at surgery. Follow the instructions you are given after your own operation rather than these.
How many levels are involved, and whether any of them is unstable, decides both the size of the operation and whether a fusion is part of it. Bring any MRI, CT or X-rays you already have.