Intervertebral disc are cartilaginous pads between the each bone of the spinal column. They have an outer fibrous layer commonly referred to as the annulus fibrosus and an inner soft core called the nucleus pulposus. The nucleus of the disc is a soft, jelly like substance that acts as shock absorber. They are held in place through ligaments and make your spine resistant to compressive forces and allow movement.
When the spine moves the intervertebral disc moves with it, this results in some amount of normal bulging of the disc. A disc bulge occurs when the outer portion of the annulus fibrosus extends beyond the adjacent vertebrae. Sometimes, due to aging or trauma this disc can become deformed and bulge out of the space it occupies. It is considered abnormal when the bulging exceeds 25% of the circumference of an intervertebral disc.
Disc bulges are often associated with bowing of the vertebral bones and, are responsible for the height loss that is seen with aging, because the disc protrudes into the spinal canal, it can compress a nerve root. Disc bulges can also be due to disc prolapse, disc herniation or disc extrusion.
Bulging can be caused by loss of structural integrity of the annulus, loss of disc space height, loose ligaments, and in response to adjacent pathology or deformities.
Disc bulges are often the result of a gradual, aging-related wear and tear called disc degeneration. Research indicates that repetitive flexion (bending or twisting) of the spine plays a role in the formation of disc bulges.
It can be difficult to know the exact cause of the disc bulges. In some instances, it can be caused by lifting up heavy objects improperly, due to bending or twisting, and rarely it can occur due to a traumatic event like falling down stairs. However, there are some predictable factors that put you at risk of a disc bulges, such as, being obese, labour intensive occupations, genetic predispositions and smoking.
The symptoms experienced depend on which disc is affected and any nearby structures such as nerves are involved. In most cases, the bulging disc may cause referred pain. This means that the pain is felt in an area other than actual site of the disc bulge. Symptoms of disc bulging are pain, tingling or numbness, weakness in muscular movement.
In more severe bulging, the disc may put pressure on the spinal cord or spinal nerves, causing conditions like spinal stenosis or sciatica or a pinched nerve.
A disc bulge could occur due to multiple factors. For a specific diagnosis, a review of your medical history, physical examination and diagnostic imaging scans is necessary.
Physical examination: Physical examination involves estimating the degree of motion, site of pain and evaluation of nerve and muscle using specific movements. In many cases, no symptoms may be apparent. You may only find out through spinal imaging and scans like MRI, CT and X-rays
Diagnostic imaging: Imaging studies such as X-rays, CT scans and MRIs may be ordered to investigate extent of degenerative changes and helps visualise all involved tissues like bone, muscles, nerves, ligaments and cartilage.
For less severe cases of disc bulge, surgery may not be necessary. Many bulged discs heal on their own.
Patients may be given pain killers to help manage their pain. Physiotherapy than also be beneficial for some people, by strengthening back muscles and through nerve decompression. Nonetheless, treatment for pain may be necessary for some patients, steroid injections, nerve blocks and more.
If the bulged disc progresses to herniation, doctors may suggest minimally invasive spine surgery, such as endoscopic surgery. In most cases, this surgery involves removal of the protruding portion of disc. Only rare cases will be more intensive and involve full disc removal. The risks of these procedures are very low, and recovery is quicker than more invasive methods.