A common consequence of a herniated disc, spinal stenosis is the narrowing of the spaces in the spinal canal which can cause back pain, sciatica, and other radicular pain throughout the body. The intervertebral discs which lie between each level of the spine are formed from a soft gelatinous material inside (the nucleus pulposus) and a fibrous outer shell to keep the shape of the disc. The nucleus pulposus has a shock absorbing action and cushions the spine during everyday movements, thereby allowing flexibility and providing support in order to stop the hard bones from colliding and damaging each other.
When damage occurs to these discs, whether through general wear and tear, smoking and dehydration, poor nutrition, excess weight-bearing, or through acute trauma, the ability to maintain the disc’s shape and height can be adversely affected. Degeneration of the disc reduces both the height of the disc and its ability to absorb shocks to the spine, and disc degeneration is largely irreversible. Intervertebral discs are avascular tissue, meaning that they have no direct circulation, similar to some types of cartilage elsewhere in the body such as the knee. A dry and brittle disc is more likely to rupture when placed under pressure, and more likely to bulge prior to herniation. Disc bulging is where the outer shell (the annulus fibrosus) does not split but is stretched out of shape by material from the nucleus pulposus. A disc bulge or a herniated disc can then cause compression of the spinal nerves or blood vessels and contribute to spinal stenosis.
Bulging discs can go undetected for years and remain asymptomatic. Sudden disc herniation or bulging can occur however, through acute stress or as a result of continuous degeneration of the disc. Herniated disc spinal stenosis may be the origin of neck and back pain as well as pain that radiates through the upper or lower limbs, such as sciatica. Where the discs have degenerated the spine can become compressed, meaning that the intervertebral height reduces and the bones of the spine rub together or begin to slip into an abnormal curve. Degeneration of the bones of the facet joints and/or vertebrae can occur as they rub together and bone spurs (osteophytes) often arise as an attempt by the body to stabilize the spine. Further spinal stenosis may then occur, due to osteophytes, increasing the risk of nerve compression in the spinal column.
Diagnosing Spinal Stenosis and Herniated Disk
Herniated disc spinal stenosis in combination with ankylosing spondylitis, rheumatoid arthritis, or osteoarthritis can seriously compromise a person’s mobility and cause chronic, progressive back pain. To diagnose a herniated disc a physician would usually use imaging techniques such as X-Ray, MRI or CT scans. The symptoms of the herniation or bulge may indicate which level of the spine has problems as individual spinal nerve compression can create pain, paraesthesia, numbness, and weakness in places far away from the spine that are innervated by a specific nerve; pain maps are often useful for isolating the likely vertebral level involved in the condition. In many cases a herniated disc is indicative of more widespread degeneration in the spine and nearby discs are also likely to be compromised. Where this is the case it may be advisable to initiate treatment for these discs to prevent further pain and disability.
Herniated Disc Spinal Stenosis Treatment
Treatment for herniated disc spinal stenosis is fairly limited with surgical removal of the offending material the only real course of action for many. Most patients will have at least six months of conservative treatment first, involving NSAIDs, possible cortisone injections, analgesics, and non-surgical spinal decompression combined with physical therapy. If, after these measures have been tried, there is no improvement and symptoms are unmanageable by the patient then back surgery may be offered. In some cases a disc bulge will resolve itself and the outer shell of the disc heals, thereby removing the cause of spinal stenosis and back pain.
Disc herniation is unlikely to resolve of its own accord and the material from the inside of the disc can irritate the spinal nerves and cause inflammation and scarring. Removing the disc fragments is a fairly standard procedure and may be performed using endoscopic surgical techniques. A discectomy may be full or partial and may be isolated to one level or extended across a number of levels if other discs are also implicated in pain. Complete removal of the disc, or even partial removal, affects the structure and support of the spine. Some patients may, therefore, require a spinal fusion surgery, or artificial disc replacement, to maintain the spine’s stability and mobility. Anterior discectomy with fusion, or posterior discectomy with spinal fusion back surgery may be conducted, along with posterior or transforaminal lumbar interbody fusion (PLIF or TLIF), and other spinal fusion surgeries in order to restore or maintain the spine’s natural curve. These surgeries usually have considerable recovery times and often transfer stresses and strains to the intervertebral discs above and below the operated level, often leading to further surgery in the future. Those with multiple disc herniations are unlikely to benefit from spinal arthroplasty (artificial disc replacement) and usually undergo spinal fusion instead.
Improvements in surgical techniques mean that some patients can avoid major open spinal fusion surgery in some cases, and there are even those who avoid surgery all together through the use of stem cell injections for herniated discs although these treatments are currently unproven in clinical trials. Herniated discs may be referred to as a ‘slipped disc’ and is a common cause of back pain that rarely resolves on its own. Poor posture, poor nutrition, and acute trauma are just some of the causes of herniated disc spinal stenosis which is difficult to prevent but even harder to treat.