First, what is a Disc?
An intervertebral disc is a soft piece of tissue that sits between the vertebrae in the spine acting as a shock absorber and gives the spine flexibility. The two main parts of a disc are the annulus fibrosus (the outer part) and the nucleus pulposus (the inner part). The annulus fibrosus is the tough outer layer and the nucleus pulposus is the core of the disc and consists of a gel-like fluid with some fibrous structure. The intervertebral disc is also highly innervated and vascularised meaning it gets good blood supply and has lots of sensation.
Is a bulging disc the same as a herniated disc? What’s the difference?
A herniated disc (ruptured disc) is when the nucleus pulposus of the disc pushes out of the annulus fibrosus and can put pressure on nearby nerves or the spinal cord. This may lead to pain, numbness, pins & needles and/or weakness in parts of the body supplied by the nerve that is being compressed.
A bulging disc occurs when the outer layer of the disc (annulus fibrosus) is weakened or damaged and expands outwards, but the core of the disc remains within. The symptoms of a bulging disc are somewhat like a herniated disc but usually less severe.
What does it feel like to have a disc injury?
The most common symptom of a disc injury is pain. This pain can be felt at the site of the injured disc (most commonly the lower back or neck) but also in the arms or legs depending on which nerves are affected. Another common symptom is a sensation of pins and needles or numbness in the arms or legs. Other more serious signs of a disc injury include weakness of muscles that are controlled by the affected nerve, abnormality in the reflexes in a limb and loss of bowel and bladder control. The common mechanisms that lead to disc injury include age related degeneration, repetitive strain, or acute trauma.
How do you know if you have a bulging disc?
A physiotherapist can make a clinical diagnosis of disc related injury by taking a detailed history, conducting a thorough physical examination, and observing and monitoring the progression of your symptoms. Imaging is not usually required unless the signs of severe neurological compromise are present such as progressive weakness and loss of bowel and bladder control. Generally imaging is not recommended unless physiotherapy has not improved symptoms after 6 weeks or the signs and symptoms of disc injury are progressively worsening.
Why do we wait so long to request imaging?
It is proven that many people without any back pain have evidence of disc degeneration, herniation and bulging and display no clinical signs or symptoms. Due to this fact, imaging is only used to confirm a clinical diagnosis or to investigate if conservative back pain treatments are failing to improve pain. Imaging too early can muddy the waters and cause clinicians and patients to focus on something that may really have little to no effect on a person’s pain, delaying recovery and possibly increasing a patient’s stress.
Common myths and misconceptions:
You cannot ‘slip’ a disc:
Although this term gets thrown around a lot, it is impossible to ‘slip’ a disc. The disc is secured to the vertebrae by very strong, thick ligaments.
Bulging discs always cause pain:
False. Up to 60% of people who have a bulging disc have no pain or symptoms.
Bulging discs always require surgery:
False. For most people, physiotherapy is effective for treating disc injuries. Surgery is indicated if conservative therapies fail or there is significant nerve compression.
Herniated discs do not heal:
False. The recovery rate of herniated discs is quite high.
Herniated discs can only be treated surgically:
False. A large proportion of people with herniated discs can improve their condition with physiotherapy tailored to their specific condition and some adjunct therapies such as anti-inflammatory medications and injections.
Herniated discs mean you are in a lot of trouble:
Not always. If your imaging shows you have a herniated disc it doesn’t necessarily point to the source of your pain. Discs degenerate as we age and have some degeneration is not a disaster, it's expected. Most people would have some degree of disc herniation somewhere in the later stages of life, although only a small percentage have pain.
What options do you have for treatment?
Physiotherapy
With adherence to a physiotherapy program including specific exercises, manual therapy, and activity modification most people will show improvement in symptoms within a few weeks to a few months. Those who seek treatment earlier are more likely to recover quickly.
Corticosteroid injections:
Corticosteroid injections can provide short-term pain relief for some people with herniated or bulging discs. Corticosteroid injections provide moderate pain relief for up to 6 weeks, but they aren’t without risks.
Some risks associated with Corticosteroid injections include infection, nerve damage and blood sugar complications in those people with diabetes. The benefits of these injections decrease over time with no benefit lasting beyond 3 months. Repeated use of these injections can lead to weight gain, osteoporosis/ fractures, high blood pressure/ heart disease and impaired wound healing amongst other things.
Corticosteroids can be a good option for people with herniated or bulging discs, but their use should not be the first line of treatment.
Surgery
Surgery should be reserved for when conservative therapy has been tried and failed or when there are significant neurological symptoms. Having surgery does not always relieve all the symptoms a person may have and doesn’t prevent the injury from happening again. Surgery should be a last resort as it carries a substantial financial cost and exposes you to risk of infection, nerve damage or other side effects of sedatives, antibiotics and analgesics. If the vertebrae are fused in the process of repairing the disc injury, you will also lose range of motion through the fused levels as well as increase the likelihood of degeneration of the discs above and below the fusion site.