What is Lumbar Spinal Stenosis?
Your spinal cord is a bundle of nerves that runs through a tunnel formed by the bones in your spine. The tunnel is called the spinal canal which holds the spinal cord, nerve roots, and spinal fluid. Lumbar spinal stenosis is a narrowing of the spinal canal in the lower part of your back. Stenosis, which means narrowing, can cause pressure on your spinal cord or the nerves that go from your spinal cord to your arms or legs.
Spinal stenosis can happen in any part of your spine but is most common in the lower back also known as your lumbar spine.
Lumbar spinal stenosis refers to the compression or pinching of spinal contents in the lumbar spine.
What are the symptoms of Lumbar Spinal Stenosis?
The compression of spinal contents causes pain that is reported as pain in the low back, buttocks, thighs and/or legs. Lumbar spinal stenosis is a significant contributor to pain and disability in the elderly and the incidence increases with age due to an increase in degenerative changes in the spine. The pain is often worse with activity, specifically walking and/or standing for extended periods of time. When spinal stenosis becomes severe, it can progress to loss of sensation and weakness.
What causes Lumbar Spinal Stenosis?
There are several causes of lumbar spinal stenosis such as a
- Being born with a small spinal canal
- Conditions lead to overgrowth of bone (Paget’s disease)
- Increased fat at in the epidural space
- Degenerative changes in the lumbar spine lead to lumbar spinal stenosi
- Disc degeneration or bulge
- Facet joint enlargement
- Thickened ligaments
- Slippage of a bone in your spine
Degeneration of the spine is typically started by disc degeneration. The discs are the cushion between the bones that make up your spine. Once this cushion is lost, the joints in the spine experience more load bearing and this leads to creation of bone spurs/osteophytes. Due to the change in load, the ligament begins to overgrow and can cause compression. Eventually, further progression of this degeneration can lead to instability and slippage of one bone over another that can further narrow the spinal canal.
Symptoms of Spinal Stenosis
- Discomfort in your low back, buttocks, thigh, and legs
- Pain, cramping or weakness when you walk
- Less pain while sitting or leaning forward
- Pain when running or golfing
- Improvement of pain with bending forward, leaning over a shopping cart, or sitting down
- Poor balance
- Constant pain and/or numbness in your legs while standing
- Increased pain and/or numbness in your legs while bending the spine backward
- Difficulty in performing upright exercises or activities
How is spinal stenosis diagnosed?
A diagnosis of lumbar spinal stenosis can be made by taking a thorough history and performing a physical examination. It is fairly common in the elderly and a description of their symptoms is the first clue. On a physical exam, they may exhibit poor balance, wide based gait, decreased reflexes, decreased sensation, and/or weakness. Advanced imaging of the lumbar spine such as CT or MRI will reveal decreased area in the spinal canal. This is most commonly seen between L4 and L5 in patients with lumbar stenosis. However, it is important to note that not all patients with spinal stenosis on imaging are symptomatic because of it. Physicians must also rule out other conditions which may have similar symptoms to spinal stenosis such as peripheral vascular disease (PVD), hip osteoarthritis (OA), etc.
So generally the steps to diagnose are:
- History and physical examination
- Rule out other causes
- Imaging of the spine
What are the conservative treatments of Lumbar Spinal Stenosis?
There are several conservative treatments available such as:
- Physical Therapy
- Home exercise program
- Nerve pain medications
Once a diagnosis of lumbar spinal stenosis has been established, the first line of treatment involves physical therapy, home exercise program and/or over the counter medications. Over the counter anti-inflammatory medications such as acetaminophen and nsaids can be effective in minimizing the pain. Nerve pain medications like gabapentin and duloxetine may also be of benefit and reasonable to consider. Patients do report improvement with an exercise regimen, however they often require guidance on activity modification as maintaining their spine in a flexed position is what brings them the most relief. So, cycling or swimming with a side stroke can be a good modification. Additionally, walking on a treadmill, aquatic therapy, stretching, increasing endurance of trunk muscles etc. has also been shown to be of benefit.
What are the interventional treatment options for Lumbar Spinal Stenosis?
There are many options available to help reduce or treat the pain from Lumbar Spinal Stenosis.
- Epidural steroid injections
- Spacer devices (Vertiflex Superion, Minuteman)
- Minimally Invasive Lumbar Decompression (MILD)
- Surgical decompression
Patients that are not responding to conservative measures can consider epidural steroid injections for pain relief. Additionally, if they feel that the pain is so limiting that they cannot participate in an exercise program because of it, then they can consider an epidural steroid injection so the pain relief can help them increase their effort in therapy. Minimally invasive options such as interspinous process spacer devices (Vertiflex Superion) are a good alternative to major spine surgery. These procedures can be done in an outpatient setting with quick recovery and good results in the appropriately selected patient. Patients with ligament thickening can benefit from a minimally invasive lumbar decompression (MILD) procedure that is designed to clip portions of the overgrown ligament and provide quick symptomatic relief with easy recovery.
In certain cases, where patients have failed all minimally invasive options and/or report significant neurologic issues then they may consider surgical decompression with/without fusion based on their individual anatomy. Lumbar spinal stenosis is a common condition, but with recent advances in interventional pain management there are several minimally invasive options that can be performed in the outpatient setting with quick recovery. Patients have many more options for pain management with great results.