The intervertebral disc are rubber-like pads sandwiched between the bones of the spinal column. They are held in place through ligaments and act as shock absorber for the spine.
They have an outer fibrous layer commonly referred to as the annulus fibrosus and an inner substance called the nucleus pulposus. The nucleus of the disc is a soft, jelly like substance that acts as a shock absorber for your body.
What is a disc tear?
A disc tear is any thinning or tear that occur in the intervertebral disc; it can be broadly categorised as two types, annular tear and disc rupture.
Annular tear:
An annular tear is a tear in the ligament that connects your vertebra to your disc. This ligament surrounds the nucleus of your disc with a strong ring of cartilage fibres called the annulus fibrosus.
A tear occurs if the ligament or the outer cartilage tears due to strain or thinning due to age. If no disc material (nucleus pulposus) seeps out, it is referred to as just an annular tear.
The outer fibrosus ring contains plenty of nerve fibres hence, tears can be extremely painful. Although an annular tear will normally heal itself over time, it is susceptible to future weakness and tears.
Disc rupture:
A disc rupture is also called a slipped disk or a herniated disk. It occurs when some of the nucleus pulposus pushes out through a tear in the annulus. It can occur in any part of the spine and can irritate a nearby nerves.
Depending on where the herniated disk is, it can result in pain, numbness or weakness in an arm or leg. Most disc ruptures occur in the lower back, although they can also occur in the neck.
Causes of disc tears
Disc tears are often the result of a gradual, aging-related wear and tear called disc degeneration. As you grow older, your discs become less flexible and more prone to tearing or rupturing with even a minor strain or twist.
It can be difficult to discern the exact cause of the disc tear in most people. Sometimes it can be caused by lifting up heavy objects improperly, due to bending or twisting rarely, or a traumatic event like a step fall or blow to the back. However, there are some predictable factors that put you at risk of a disc tear, such as, excess body weight, strenuous occupations, genetic predispositions and smoking.
Signs and symptoms of disc tears
Signs and symptoms depend on where the disc is situated and whether the disc is pressing on a nerve.
- You may experience arm or leg pain. If the disc tear is in the neck you may feel pain in your arm and shoulder. If the tear is in your lower back you may experience pain in your buttocks, thigh, calf or foot. This pain is often described as sharp or burning.
- You may experience numbness or tingling sensation in the areas that the compressed nerve supplies.
- You may feel weakness, this may present as a difficulty to grasp items, lift things or even as stumbling.
In many cases, no symptoms may be apparent. You may only find out through spinal imaging.
Diagnosis of disc tear
A disc tear is diagnosed based on the correlation of the symptoms from your medical history, physical examination and diagnostic imaging scans.
Physical examination: Physical examination involves assessing the degree of motion, site of pain and evaluation of nerve and muscle using specific movements.
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.
These evaluations can help determine the severity and location of the disc tear and predict any risk of herniation. Your diagnosis is useful in the creation of a suitable course of treatment.
Available treatments
Usually, non-surgical methods of treatment are attempted first.
Pain medications may be prescribed to alleviate pain and allow the patient to begin exercising and stretching. There are a number of non-surgical methods used in attempts to relieve the condition. However, if it doesn’t get better or person develops complications like worsening symptoms of pain, numbness or weakness or loss of bladder control or bowel dysfunction, surgery may be considered.
Some common surgical procedures are:
- Discectomy: It is the partial removal of a disc that is causing leg pain. This can provide pain relief sooner than non-surgical treatments.
- Small endoscopic discectomy: This is a non-invasive treatment and preserves integrity of the back.
- Invasive micro-discectomy: It is done with a one-inch skin opening and involves complete or partial removal of a damaged intervertebral disc.
Potential complications of surgery
Failed back syndrome is a significant, potentially disabling, result that can arise following invasive spine surgery to treat disc herniation. However, smaller spine procedures such as endoscopic lumbar discectomy do not cause failed back syndrome, because no bone is removed.
