In many cases, the conditions causing Spinal Stenosis cannot be cured by nonsurgical treatment, even though these measures may relieve pain for a period of time. The effectiveness of nonsurgical treatments, the extent of the patient's pain, and the patient's preferences may all factor into whether or not to have surgery.
Surgery might be considered immediately if a patient has numbness or weakness that interferes with walking or impairs bowel or bladder function.
The purpose of surgery is to relieve pressure on the nerves, as well as restore and maintain the alignment of the spine. This can be done by decompressive laminectomy, i.e. removal of the lamina (roof) of one or more vertebrae to create more space for the nerves.
If the affected spinal segment is also deemed to be unstable (e.g. spondylolisthesis or lateral subluxation in degenerative scoliosis) or responsible for a significant proportion of the patient's axial back pain, fusion may also be performed at the same setting.
Fusion often involves the use of the patient's own bone from the removed lamina or facet, supplemented by titanium pedicle screws. Various methods may be used to enhance fusion and strengthen unstable segments of the spine following decompression surgery. For example, one can use interbody cages placed in the intervertebral disc spaces after discectomy.
One advancement in the surgical fusion technique is the use of BMP (bone morphogenetic protein) to improve the fusion success rate, especially in patients with higher risks of nonunion - for example, diabetics, smokers, patients who have had multi-level surgeries, and revision surgeries.
The buzz words in spine surgery nowadays are non-fusion surgery and minimally invasive surgery. These techniques are now applicable in the surgical treatment of Lumbar Spinal Stenosis in carefully selected patients.
Non-fusion surgery is possible with the use of dynamic devices (e.g. interspinous spacers) placed after decompression laminectomy in order to restrict - but not completely eliminate - spinal motion at the affected level. Minimally-invasive surgery is now possible with the use of specially designed ports and screw systems, with the added advantage of reduced hospital stay and an earlier return to work.