Herniated Disc

Overview

The bones (vertebrae) that form the spine in the back are cushioned by discs. These discs are round, like small pillows, with a tough, outer layer (annulus) that surrounds the nucleus. Located between each of the vertebra in the spinal column, discs act as shock absorbers for the spinal bones.

A herniated disc (also called bulged, slipped or ruptured) is a fragment of the disc nucleus that is pushed out of the annulus, into the spinal canal through a tear or rupture in the annulus. Discs that become herniated usually are in an early stage of degeneration. The spinal canal has limited space, which is inadequate for the spinal nerve and the displaced herniated disc fragment. Due to this displacement, the disc presses on spinal nerves, often producing pain, which may be severe.

Herniated discs can occur in any part of the spine. Herniated discs are more common in the lower back (lumbar spine), but also occur in the neck (cervical spine). The area in which pain is experienced depends on what part of the spine is affected.

Causes

A single excessive strain or injury may cause a herniated disc. However, disc material degenerates naturally as one ages, and the ligaments that hold it in place begin to weaken. As this degeneration progresses, a relatively minor strain or twisting movement can cause a disc to rupture.

Certain individuals may be more vulnerable to disc problems and, as a result, may suffer herniated discs in several places along the spine. Research has shown that a predisposition for herniated discs may exist in families with several members affected.

Symptoms

Symptoms vary greatly, depending on the position of the herniated disc and the size of the herniation. If the herniated disc is not pressing on a nerve, the patient may experience a low backache or no pain at all. If it is pressing on a nerve, there may be pain, numbness or weakness in the area of the body to which the nerve travels. Typically, a herniated disc is preceded by an episode of low back pain or a long history of intermittent episodes of low back pain.

Lumbar spine (lower back): Sciatica/Radiculopathy frequently results from a herniated disc in the lower back. Pressure on one or several nerves that contribute to the sciatic nerve can cause pain, burning, tingling and numbness that radiates from the buttock into the leg and sometimes into the foot. Usually, one side (left or right) is affected. This pain often is described as sharp and electric shock-like. It may be more severe with standing, walking or sitting. Straightening the leg on the affected side can often make the pain worse. Along with leg pain, one may experience low back pain; however, for acute sciatica the pain in the leg is often worse than the pain in the low back.

Cervical spine (neck): Cervical radiculopathy is the symptoms of nerve compression in the neck, which may include dull or sharp pain in the neck or between the shoulder blades, pain that radiates down the arm to the hand or fingers or numbness or tingling in the shoulder or arm. The pain may increase with certain positions or movements of the neck.

When & How to Seek Medical Care

Fortunately, the majority of herniated discs do not require surgery. With time, the symptoms of sciatica/radiculopathy improve in approximately 9 out of 10 people. The time to improve varies, ranging from a few days to a few weeks.

General Guidelines:

• Limit activities for 2 to 3 days. Walking as tolerated is encouraged, along with an anti-inflammatory, such as ibuprofen, if not contraindicated for the patient. Bedrest is not recommended.
• Primary care evaluation during this time may lead to considering other non-surgical treatments noted below, such as physical therapy.
• Radiographic imaging, such as an MRI, is not recommended by the American College of Radiology, unless symptoms have been present for six weeks.
• Referral to a spine specialist, such as a neurosurgeon, is also recommended if symptoms persist for greater than four weeks. A specialist will often want advanced imaging, such as the MRI, completed prior to the appointment.
• Urgent evaluation and imaging is recommended if there are symptoms of significant leg/arm weakness, loss of feeling in the genital/rectal region, no control of urine or stool, a history of metastatic cancer, significant recent infection or fever AND radiculopathy or a fall/injury that caused the pain. Imaging should also be considered earlier for findings of progressive neurologic deficit (such as progressive weakness) on exam.

Testing & Diagnosis

Testing modalities are listed below. The most common imaging for this condition is MRI. Plain x-rays of the affected region are often added to complete the evaluation of the vertebra. Please note, a disc herniation cannot be seen on plain x-rays. CT scan and myelogram were more commonly used before MRI, but now are infrequently ordered as the initial diagnostic imaging, unless special circumstances exist that warrant their use. An electromyogram is infrequently used.

• X-ray: Application of radiation to produce a film or picture of a part of the body can show the structure of the vertebrae and the outline of the joints. X-rays of the spine are obtained to search for other potential causes of pain, i.e. tumors, infections, fractures, etc.
• Computed tomography scan (CT or CAT scan): A diagnostic image created after a computer reads X-rays; can show the shape and size of the spinal canal, its contents and the structures around it.
• Magnetic resonance imaging (MRI): A diagnostic test that produces 3D images of body structures using powerful magnets and computer technology; can show the spinal cord, nerve roots and surrounding areas as well as enlargement, degeneration and tumors.
• Myelogram: An X-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces; can show pressure on the spinal cord or nerves due to herniated discs, bone spurs or tumors.
• Electromyogram and Nerve Conduction Studies (EMG/NCS): These tests measure the electrical impulse along nerve roots, peripheral nerves and muscle tissue. This will indicate whether there is ongoing nerve damage, if the nerves are in a state of healing from a past injury or whether there is another site of nerve compression. This test is infrequently ordered.

Treatment

Non-Surgical Treatments

The initial treatment for a herniated disc is usually conservative and nonsurgical. A doctor may advise the patient to maintain a low, painless activity level for a few days to several weeks. This helps the spinal nerve inflammation to decrease. Bedrest is not recommended.

A herniated disc is frequently treated with nonsteroidal anti-inflammatory medication, if the pain is only mild to moderate. An epidural steroid injection may be performed utilizing a spinal needle under X-ray guidance to direct the medication to the exact level of the disc herniation.

The doctor may recommend physical therapy. The therapist will perform an in-depth evaluation, which, combined with the doctor’s diagnosis, dictates a treatment specifically designed for patients with herniated discs. Therapy may include pelvic traction, gentle massage, ice and heat therapy, ultrasound, electrical muscle stimulation and stretching exercises. Pain medication and muscle relaxants may also be beneficial in conjunction with physical therapy.

Surgery

A doctor may recommend surgery if conservative treatment options, such as physical therapy and medications, do not reduce or end the pain altogether. Doctors discuss surgical options with patients to determine the proper procedure. As with any surgery, a patient’s age, overall health and other issues are taken into consideration.

The benefits of surgery should be weighed carefully against its risks. Although a large percentage of patients with herniated discs report significant pain relief after surgery, there is no guarantee that surgery will help.

A patient may be considered a candidate for spinal surgery if:

• Radicular pain limits normal activity or impairs quality of life
• Progressive neurological deficits develop, such as leg weakness and/or numbness
• Loss of normal bowel and bladder functions
• Difficulty standing or walking
• Medication and physical therapy are ineffective
• The patient is in reasonably good health

Lumbar Spine Surgery

Lumbar laminotomy is a procedure often utilized to relieve leg pain and sciatica caused by a herniated disc. It is performed through a small incision down the center of the back over the area of the herniated disc. During this procedure, a portion of the lamina may be removed. Once the incision is made through the skin, the muscles are moved to the side so that the surgeon can see the back of the vertebrae. A small opening is made between the two vertebrae to gain access to the herniated disc. After the disc is removed through a discectomy, the spine may need to be stabilized. Spinal fusion often is performed in conjunction with a laminotomy. In more involved cases, a laminectomy may be performed.

In artificial disc surgery, an incision is made through the abdomen, and the affected disc is removed and replaced. Only a small percentage of patients are candidates for artificial disc surgery. The patient must have disc degeneration in only one disc, between L4 and L5, or L5 and S1 (the first sacral vertebra). The patient must have undergone at least six months of treatment, such as physical therapy, pain medication or wearing a back brace, without showing improvement. The patient must be in overall good health with no signs of infection, osteoporosis or arthritis. If there is degeneration affecting more than one disc or significant leg pain, the patient is not a candidate for this surgery.

Cervical Spine Surgery

The medical decision to perform the operation from the front of the neck (anterior) or the back of the neck (posterior) is influenced by the exact location of the herniated disc, as well as the experience and preference of the surgeon. A portion of the lamina may be removed through a laminotomy, followed by removal of the disc herniation for the posterior approach. Patients, who are a candidate for posterior surgery, frequently do not need surgical fusion. For anterior surgery, after the disc is removed, the spine needs to be stabilized. This is accomplished using a cervical plate, interbody device and screws (instrumentation). In a select group of candidates, artificial cervical disc is an option vs. fusion.

Follow-up

The doctor will give specific instructions after surgery and usually prescribe pain medication. He or she will help determine when the patient can resume normal activities, such as returning to work, driving and exercising. Some patients may benefit from supervised rehabilitation or physical therapy after surgery. Discomfort is expected during a gradual return to normal activity, but pain is a warning signal that the patient might need to slow down.

Resources

1. KnowYourBack.org. (2019). Herniated Lumbar Disc. https://www.spine.org/KnowYourBack/Conditions/DegenerativeConditions/HerniatedLumbarDisc