Most patients have heard the phrase "slipped disc" or "ruptured disc." Some may be familiar with the medical term "radiculopathy". What these terms most often refer to is irritation of a spinal nerve root secondary to compression by a herniated disc. While there are other causes of nerve root irritation, disc herniations are the most common, especially in the low back. It is probably the #1 condition treated by interventional spine physicians.
Disc herniations may occur in the cervical, thoracic, and lumbar spine. Each region has a typical set of symptoms patients may experience. Symptoms of a disc herniation may include the following:
- A lumbar herniated disc is a common cause of low back, buttock, and leg pain. Sciatica is a term used to describe pain extending into (usually one leg) the leg.
- Other associated symptoms that may occur include numbness, tingling, and/or burning in the leg on the affected side.
- Movements or activities such as bending, coughing, or sneezing may intensify the pain.
- Muscle spasms or cramping.
- Leg weakness or loss of leg function.
- A thoracic herniated disc is a common cause of mid back and rib/abdominal pain.
- The symptoms may even be confused for other medical conditions like:
- Cholecystitis (inflammation of the gall bladder)
- Appendicitits (infection of the appendix)
- A cervical herniated disc is a common cause of neck and arm/shoulder pain.
- Other associated symptoms that may occur include numbess, tingling, and/or burning in the arm on the affected side.
- Movements or activities such as bending, coughing, or sneezing may intensify the pain. Turning the head toward the affected side may also aggravate the patient’s symptoms.
- Arm weakness or loss of arm function.
How Do Discs Herniate?
Discs, which act as shock absorbers for the spine, are located in between each of the vertebral body in the spine. Each disc contains a tire-like outer band (called the annulus fibrosus) that surrounds a gel-like substance (called the nucleus pulposus).
A herniation occurs when the outer band of the disc partially or fully cracks and the gel-like substance from the inside of the disc leaks out, placing pressure on the spinal canal or nerve roots. In addition, the nucleus releases chemicals that can irritate the surrounding nerves causing inflammation and pain.
While some disc herniations occur as a result of sudden stress, such as from an accident, most occur gradually, over weeks or even months. The risk factors that can contribute to the chances of a disc herniation, include:
- Aging. As we get older, discs gradually dry out, losing their strength and resiliency.
- Lifestyle choices. Poor choices include a lack of regular exercise, eating an unhealthy diet, being over-weight, and tobacco use contribute to disc problems.
- Poor posture, incorrect and/or repetitive lifting or twisting can place additional stress on the lumbar spine.
DiagnosisGood treatment is always based on an accurate diagnosis. A comprehensive diagnostic process includes:
- Medical history. Your physician will talk to you about your symptoms, their severity, and what treatments you have already tried.
- Physical examination. You will be carefully examined for limitations of movement, problems with balance, and pain. During the neurological part of the physical exam, your physician will examine your reflexes, muscle strength, areas of weakness, and abnormal or loss of sensation.
- Diagnostic tests.
- MRI. MRI provides the most accurate three-dimensional views of the lumbar spine and can help detect herniated discs. It can also help rule out other disorders of the spine that may mimic the symptoms of a disc herniation.
- EMG. EMG is an electrodiagnostic study (nerve test) that may help clarify definite injury to one particular nerve root. This test may also give the physician feedback as to the severity of this nerve injury.
- Diagnostic Selective Nerve Root Block. A diagnostic selective nerve root block (SNRB) is similar to other spinal injections that a patient may undergo. However, this injection is purely diagnostic in nature (not a treatment), aiding you physician in confirming your suspected diagnosis.
Treatment for Lumbar Disc Herniation
The good news is that most cases of lumbar disc herniation do not require surgery! Long-standing evidence suggests that pain associated with a herniated disc often diminishes without surgical treatment within 3-6 months. Unfortunately, it is difficult to predict which cases will have natural resolution, and which will not. Thus, patients are usually prescribed non-surgical treatments initially to help relieve symptoms.
A combination of the following treatments will be used with most herniated disc patients:
- Anti-inflammatory medications help reduce swelling and pain
- Narcotic painkillers are prescribed to alleviate acute pain (only if absolutely necessary)
- Physical therapy. An exercise prescription tailored to your condition is provided to your your physical therapist. A typical prescription involves:
- Stretching exercises
- Strengthening exercises
- Core stability training
- Balance training
- A therapeutic selective nerve root block (SNRB) series
- Most patients will benefit from a type of pinpoint epidural injection, performed under live x-ray guidance, of a strong anti-inflammatory medication (corticosteroid).
- Maximum benefit typically occurs following 2 to 4 injections
Percutaneous Disc Decompression
Although most patients improve with conservative non-invasive therapy (see "Non-operative Treatment" above), numerous patients continue to experience significant pain. Open surgical procedures are available; however, these procedures are associated with a small, but not insignificant, risk of complications such as nerve root injury, excessive scarring around nerve roots, mechanical instability, bleeding, and infection. It has therefore become increasingly important that spine specialists consider minimally invasive procedures for these patients and progress to more invasive interventions only if necessary.
This desire for a minimally invasive option for treatment of spine pain led to the development of numerous percutaneous techniques (non-surgical techniques using probes that are directed through the skin and muscle, down to the problem area in the spine using x-ray guidance). These procedures have demonstrated good to excellent results 70–75% of the time. For patients with a symptomatic focal disc protrusion (type of herniated disc), unresponsive to more conservative measures, percutaneous disc decompression has become the standard of care in interventional spine management. The implementation of this treatment option has dramatically reduced the number of patients ultimately needing lumbar surgery.
Percutaneous Disc Decompression (PDD) is a minimally invasive procedure performed under live x-ray guidance with the goal of removing a small amount of nuclear disc material (jelly-like substance in the centre of your disc) from your herniated disc. This decreases the pressure inside the disc (like deflating a water balloon), thus relieving the pressure transmitted to your nerve root. The ultimate goal is to relieve your symptoms of leg pain +/- back pain (otherwise known as "sciatica" or "radiculopathy").
Surgical TreatmentIf after a full course of interventional/medical management the patient still has intolerable pain, or if there is evidence of neurological deficit (e.g. significant weakness and/or numbness) then surgery to treat the disc herniation may be recommended.
To relieve nerve pressure and leg pain, surgery usually involves removing part or the entire damaged disc. This is called a discectomy. This procedure can often be done utilizing minimally invasive surgical techniques. Microdiscectomy uses smaller incisions and specialized technology such as microscopes and endoscopes ("mini-video cameras"). Minimally invasive surgery techniques often result in quicker patient recovery times compared to traditional techniques, as they reduce trauma to muscles and minimize bloodloss during surgery.
Spine fusion is rarely necessary when a disc is herniated for the first time. If necessary, the space left by the removed disc may be filled with a bone graft – a small piece of bone usually taken from the patient’s hip. The bone graft or a bone substitute is used to join or fuse the vertebrae together. In some cases, specially designed instrumentation (such as rods or screws) may be used to help promote fusion and to add stability to the spine.
In addition to a discectomy, a portion of the bone covering the nerve may also need to be removed. This procedure is called a laminectomy.