The more miles you put on the car the more likely you are to have wear and tear changes occur. This is a simple mechanical phenomena that applies to our spine as well. Our lumbar spine and cervical spine are multiple bones separated from each other by cushions (discs) and connected to each other via joints. This allows our spine to protect neurologic structures, absorb stress and weight, and position our body in space. Intuitively, the older we get the more likely we are to have degenerative changes that eventually can cause symptoms. A common example is spinal Stenosis. Stenosis refers to narrowing of the canal where the nerves travel to reach their ultimate destination (arms or legs).
Our spinal canal is bordered by three important anatomic structures: disc, joints (facets) and ligaments. With time, the discs can bulge and infringe upon the anterior portion of the canal. At the same time, facet joints will begin to degenerate and form bone spurs which can narrow the canal from the sides. Lastly, the ligaments (ligamentum flava) that border the posterior portion of the canal can hypertrophy and contribute to overall narrowing of the canal. The overall degenerative process that contributes to Stenosis is slow and can take many years to eventually cause enough narrowing that patients become symptomatic.
Typical patient complaints involve a loss of endurance and fatigue associated with their lower extremities. Back pain often is associated with the leg symptoms but is quickly alleviated when the patient sits. Common symptoms that identify Stenosis are changes in walking distance (decreasing over time), preference for flexed positions (sitting and sleeping in the fetal position) or leaning over the shopping cart. The body automatically prefers a flexed spinal position because the canal is at its widest dimension with flexion versus extension (standing straight).
Non-operative treatment refers to attempts to minimize the Stenosis symptoms without altering anatomy (surgery). Physical therapy (PT) is a mainstay because increased strength & endurance of our trunk our neck muscles allows for increased support of the bony architecture of the spine and minimizes irritation of degenerated anatomic parts. Anti-inflammatories (NSAIDS) contribute to pain relief by decreasing irritation. Lastly, epidural steroid shots decrease swelling and irritation of pinched nerves to achieve pain relief. Conservative measures work well because often significant relief can be obtained. In essence, these non-operative measures buy time by minimizing symptoms without altering the underlying issue; the aging spine.
After a minimum of 6-12 weeks of conservative measures, if no significant improvement has been obtained, then surgery can be discussed. Intervention for spinal Stenosis has been performed since the early 20th century. The procedure involves “decompressing” the “pinched” nerves by removing the posterior portion of the canal (lamina) via a Laminectomy. Laminectomies take anywhere from 1 to 3 hours depending on how many levels are involved. The good news is there are minimal restrictions post operatively. The vast majority of patients go home the next day with no restrictions.
Surgery quickly relieves leg symptoms. Barring any permanent nerve changes from chronic compression, patients quickly regain lost strength and walking distance with the help of PT. In certain cases, Stenosis is associated with spondylolisthesis. Listhesis refers to translation of one bone in relation to another. This “slip” can become worse after a Laminectomy at the same level. In cases like this, a concomitant fusion is added to minimize potential back pain from instability of the spine.
Risks associated with decompressive surgery are similar to most surgical procedures. The biggest risk is associated with the anesthesia itself. That is why “clearance” by a primary care physician or a cardiologist is needed to undergo a surgery. Other risks include infection, Stenosis developing at other levels, dural tears (the nerve sack rips leaking spinal fluid).
Results are generally 70-80% success at 5 years. This translates to increased walking distance, improved functionality, less leg pain and less medication use. The main reason to need follow up surgery is if Stenosis develops at levels next to the prior surgical site.
For the most part, Stenosis is a chronic degenerative process that develops over many years. Conservative measures simply control symptoms until the patient deems their quality of life is severely inhibited. At that point, surgery can be discussed. Results from decompression are often the most profound and allow patients to return to their favorite activities.