The spine comprises fibrous tissues (intervertebral discs) and bony segments (vertebrates). Together, from the head to the pelvis, the discs and vertebrates form a spinal column that gives support and symmetry. The vertebrae are divided into five different regions, each with its own unique characteristics and functions.
The topmost region of the spine is the cervical spine, which is made up of seven vertebrae. The cervical spine is responsible for supporting the head and allowing for movement of the head and neck.
The next region is the thoracic spine, which is made up of 12 vertebrae. The thoracic spine is responsible for supporting the ribcage and allowing for movement of the chest and shoulders.
The lumbar spine is the third region and is made up of five vertebrae. The lumbar spine is responsible for supporting the majority of the body’s weight and allowing for movement of the hips and lower back.
The sacral spine is the fourth region and is made up of five fused vertebrae. The sacral spine is responsible for connecting the spine to the pelvis. The final region of the spine is the coccyx, which is made up of four fused vertebrae. The coccyx is commonly referred to as the tailbone and serves as the point of attachment for certain muscles and ligaments.
Facet joints form from the superior and inferior articular processes of two adjacent vertebrae. They are synovial joints as a fibrous capsule encompasses the bone and articulating cartilage and is continuous with the periosteum. The joint also contains synovial fluid which is kept in place by an inner membrane. The function of these joints is to allow for flexion and extension of the spine while limiting rotation and preventing the vertebrae from slipping over each other. The sensory nerve of these joints is the medial branch of the dorsal spinal ramus. Facet joint disease, also known as facet syndrome, is a condition in which these joints become a source of pain. Facet joint mediated pain is a common source of disability amongst our population with significant economic impact. Chronic low back pain often results from facet joint disease, with a prevalence of 15 to 41%. Injection of steroids into the facet joints can help relieve pain for a long period of time. Other conservative approaches include anti-inflammatory drugs, and physical therapy. For long-term relief and in more severe cases, a rhizotomy (burning the anterior or posterior spinal nerve roots) may be done. Surgical interventions could be effective in relieving pain if conservative care fails.
Spinal discs are also called intervertebral discs. There is a spinal disc between each bone (vertebra) in your spine. This keeps the vertebrae separated and acts as a shock absorber. A spinal disc is a little like a jelly donut, with a softer center (nucleolus pulposus) encased within a tougher exterior (annulus fibrosus). Disc herniation, sometimes called a slipped disk, is displacement of the disc nucleus pulposus, parts of the annulus fibrosus and cartilage, beyond the limits of the intervertebral disc space.
Disc herniation is most often the result of a gradual, aging-related wear and tear called disc degeneration. As you age, your spinal discs lose some of their water content. That makes them less flexible and more prone to tearing or rupturing with even a minor strain or twist. Some people are more prone for disc herniation than others. Overweight causes extra stress on the discs in your lower back. Those with physically demanding jobs requiring repetitive lifting, pulling, pushing, bending sideways and twisting have a higher risk of a herniated disc and some people inherit a predisposition to developing disc herniation. Most people can’t pinpoint the exact cause of their herniated disc and you also can have a herniated disk without knowing it.
A herniated disc can irritate nearby nerves and result in pain, numbness or weakness in an arm or leg. The most common nerve pain caused by disc problems is sciatica – where the affected disc presses on your sciatic nerve, causing pain radiating into your leg. This nerve travels from your spine to your hip and buttock and down your leg. The pain can be sudden and sharp, and move down the nerve to your leg and sometimes down to your foot. Just below your waist, the spinal cord separates into a group of long nerve roots (cauda equina) that resemble a horse’s tail. Rarely, disc herniation can compress the entire cauda equina. If this happens emergency surgery may be required to avoid permanent weakness or paralysis.
Depending on your symptoms and signs you may need imaging by an MRI scan (magnetic resonance imaging) to confirm the diagnosis and decide on the best treatment. This will be essential if your symptoms suggest cauda equina compression.
The outlook of disc herniation is good for most people. Many people experience no symptoms from a herniated disk. For those who develop symptoms, the initial treatment is usually anti-inflammatory pain killer and an advice about simple back exercises to keep you as normally active and mobile. If the pain or any restrictions caused by the problem with your back last for more than 1-2 weeks the treatment options include physiotherapy and referral to a specialist for an epidural or nerve root corticosteroid injection if there is associated sciatic pain.
Spinal stenosis is a term used to describe a narrowing of the spinal canal. The narrowing may not cause any symptoms. However, the narrowing may progress to cause squeezing (compression) of the spinal nerves . Spinal stenosis can cause back pain and/or leg pain. Most often it occurs when you walk. Weakness of the legs may make you feel unsteady. This may affect both legs or just one leg. Usually, as part of the normal ageing process, degenerative changes occur in the spine leading to spinal stenosis. Spinal stenosis can often be treated by simple measures such as medicines for pain relief, keeping as active as you can and losing weight if you are overweight. Sometimes surgery is needed if simple measures are not successful. Very occasionally, some patient’s with spinal stenosis may develop Cauda Equina Syndrome. This is a very serious complication and if you develop any of the following warning signs, you must seek emergency medical help.