Lumbar Herniated Disc
Risk Factors, Diagnosis, Treatments
A common cause of lower back and leg pain is a lumbar ruptured disc or herniated disc. Symptoms of a herniated disc may include dull or sharp pain, muscle spasm or cramping, sciatica, and leg weakness or loss of leg function. Sneezing, coughing, or bending usually intensify the pain.
Rarely bowel or bladder control is lost, and if this occurs, seek medical attention at once.
Sciatica is a symptom frequently associated with a lumbar herniated disc. Pressure on one or several nerves that contribute to the sciatic nerve can cause pain, burning, tingling, and numbness that extends from the buttock into the leg and sometimes into the foot. Usually one side (left or right) is affected.
Anatomy: Normal Lumbar Intervertebral Disc
First, a brief overview of spinal anatomy so that you can better understand how a lumbar herniated disc can cause lower back pain and leg pain.
In between each of the 5 lumbar vertebrae (bones) is a disc—a tough fibrous shock-absorbing pad. Endplates line the ends of each vertebra and help hold individual discs in place. Every disc has a tire-like outer band (annulus fibrosus) that encases a gel-like substance (nucleus pulposus).
Disc herniation occurs when the annulus fibrous breaks open or cracks, allowing the nucleus pulposus to escape. This is called a herniated nucleus pulposus or herniated disc, although you may have also heard it called a ruptured disc or a bulging disc.
When a disc herniates, it can press on the spinal cord or spinal nerves. All along your spine, nerves are branching off from the spinal cord and travelling to various parts of your body (to help you feel and move). The nerves pass through small passageways between the vertebrae and discs, so if a herniated disc presses into that passageway, it can compress (or "pinch") the nerve. That can lead to the pain associated with herniated discs.
(In the illustration below, you can see a close-up look at a herniated disc pressing on a spinal nerve.)
Lumbar Herniated Disc Risk Factors
Many factors increase the risk for disc herniation:
- Lifestyle choices such as tobacco use, lack of regular exercise, and inadequate nutrition substantially contribute to poor disc health.
- As the body ages, natural biochemical changes cause discs to gradually dry out, which can affect disc strength and resiliency. In other words, the aging process can make your intervertebral discs less capable of absorbing the shock from your movements, which is one of their main jobs.
- Poor posture combined with the habitual use of incorrect body mechanics stresses the lumbar spine and affects its normal ability to carry the bulk of the body's weight.
Combine these factors with the affects from daily wear and tear, injury, incorrect lifting, or twisting and it is easy to understand why a disc may herniate. For example, lifting something incorrectly can cause disc pressure to rise to several hundred pounds per square inch!
How a Disc Herniates
A herniation may develop suddenly or gradually over weeks or months. The 4 stages to a herniated disc are:
1) Disc Degeneration: Chemical changes associated with aging causes discs to weaken, but without a herniation.
2) Prolapse: The form or position of the disc changes with some slight impingement into the spinal canal and/or spinal nerves. This stage is also called a bulging disc or a protruding disc.
3) Extrusion: The gel-like nucleus pulposus breaks through the tire-like wall (annulus fibrosus) but remains within the disc.
4) Sequestration or Sequestered Disc: The nucleus pulposus breaks through the annulus fibrosus and can then go outside the intervertebral disc.
How a Lumbar Herniated Disc is Diagnosed
Interestingly, not every herniated disc causes symptoms. Some people discover they have a bulging disc or herniated disc after an x-ray for an unrelated reason.
Most of the time, the symptoms, especially the pain, prompt the patient to seek medical care. The visit with the doctor usually includes a physical exam and neurological exam. He or she will also review your medical history, and ask about what symptoms you've experienced and what treatments you've tried for pain relief.
An x-ray may be needed to rule out other causes of back pain such as osteoarthritis (spondylosis) or spondylolisthesis.
A CT or MRI scan verifies the extent and location of disc damage.These imaging tests can show the soft tissues (such as the disc).
Sometimes a myelogram is necessary. In that test, you will receive an injection of a dye; the dye will show up well on a CT scan, enabling your doctor to more easily see problem areas.
Nonsurgical Treatment of Lumbar Disc Herniation
- After the initial injury, the doctor may recommend cold therapy and medications.
- During the first 24 to 48 hours, cold therapy helps to reduce swelling, muscle spasm, and pain by reducing blood flow. Never apply cold or ice directly to skin; instead wrap the ice pack or cold product in a towel and apply for no longer than 15 minutes.
- Medications may include an anti-inflammatory to reduce swelling, a muscle relaxant to calm spasm, and a pain-killer to alleviate intense but short-lived pain (acute pain).
- Mild to moderate pain may be treated with non-steroidal anti-inflammatory drugs (NSAIDs). These work by relieving both swelling and pain.
With any of these medications, please discuss use with your physician first.
- Usually, after the first 48 hours, heat therapy can be applied. Heat increases blood flow to warm and relax soft tissues. Increased blood flow helps to flush away irritating toxins that may accumulate in tissues as a result of muscle spasm and intervertebral disc injury. Never apply heat directly to skin (just as with cold); instead, wrap the heat source in a thick towel for no longer than 20 minutes.
If leg pain is severe, or leg weakness is developing, the doctor may prescribe an epidural steroid injection. An epidural steroid injection puts anti-inflammatory medication into the space near the affected nerves in your lumbar spine. You should discuss this option with your doctor and ask about potential side effects before beginning this treatment.
The doctor may recommend physical therapy. The doctor's orders are transmitted to the physical therapist by prescription. Physical therapy includes a combination of treatments to decrease pain and increase flexibility. Ice and heat therapy, gentle massage, stretching, and pelvic traction are some examples, but your physical therapist will work with you to develop the best treatment plan for your pain and other symptoms.
Here's the good news: In 4 to 6 weeks, the majority of patients find their symptoms are relieved without surgery.
Surgical Treatment of a Lumbar Herniated Disc
Spine surgery is considered if non-surgical treatment does not relieve symptoms. Constant pain, leg weakness, or loss of function requires further evaluation. Rarely, does a lumbar herniated disc cause bowel/bladder incontinence or groin/genital numbness, which requires immediate medical attention.
If surgery is recommended, always ask the purpose of the operation and what results you can expect. You need to understand all details of what is being recommended, and don't hesitate to get a second opinion from another spine surgeon. Spine surgery is a big decision, so you odn't want to rush into it.
To relieve nerve pressure and leg pain, surgery usually involves a discectomy (removal of all or part of the intervertebral disc).
In addition, the surgeon may need to access the herniated disc by removing a portion of the bone covering the nerve. This procedure is called a laminotomy.
Fortunately, these procedures can often be done utilizing minimally invasive techniques. Minimally invasive spine surgery does not require large incisions, but instead uses small cuts and tiny specialized instruments and devices such as a microscope and endoscope during the operation.
Can You Prevent a Lumbar Herniated Disc?
Earlier in this article, we told you that a common cause of a lumbar herniated disc is aging, and we can't avoid that. Does that mean that you can't do anything to prevent a lumbar herniated disc?
Of course not. There are several factors that are within your control, and to take good care of your spine, watch your posture, don't smoke, make healthy food choices, exercise, and use good body mechanics, especially when you're lifting something.
Doing all of those things won't guarantee that you never get a lumbar herniated disc, but they are generally healthy steps you can take to try to prevent lower back pain caused by a herniated disc.