May 27, 2020 - TCO
Spine Surgeon’s Guide to Herniated Discs
What is a disc herniation?
Simply put, a disc herniation is when the intervertebral disc material displaces out of its normal location.
Intervertebral discs are soft-tissue structures that link adjacent vertebrae together. They allow for motion of, and provide stability to, the spinal column. Discs are composed of an outer layer called the annulus which encases the water-rich central portion of the disc called the nucleus.
Many terms have been used to describe this diagnosis: herniated disc, herniated nucleus pulposus, ruptured disc, prolapsed disc, slipped disc, bulging disc, etc. Radiologists and doctors who treat disc herniations will commonly use more specific classification systems in their MRI reports and clinic notes, but for the sake of this article “herniated disc” is a good general term.
What causes a disc herniation and who gets them?
A single significant strain to your back may cause a lumbar disc herniation. Patients may be able to pinpoint the exact time that it occurred, such as lifting a heavy piece of furniture. In other circumstances, a disc herniation may be due to recurrent strains to the low back causing a tear in the outer layer of the disc (the annulus). A disc herniation may happen even after a seemingly minor injury to the lower back when there have been normal age-related changes that weaken the disc. There are even patients who cannot recall any sort of injury or divergence from their normal daily activities that get disc herniations.
Disc herniations occur more frequently in men than women. Men are three times more likely to sustain a disc herniation. Disc herniations typically occur in the 4th or 5th decade of life, but younger and older people are certainly not immune to getting them. Some people have a genetic predisposition (inherited risk) for degenerative disc disease and disc herniations.
What are the symptoms of a lumbar disc herniation and when should I see a doctor?
Typical symptoms of a lumbar disc herniation include pain that radiates into the buttock and lower extremity and a sensation of tingling or numbness in the leg. Some patients may even notice some muscle weakness. On occasion, patients describe a specific pain pattern in their lower extremity, which can be used to predict which level or spinal nerve is involved, even before advanced imaging is performed.
Coughing, sneezing, bending, or lifting will sometimes make the pain worse for patients. Certain positions may alleviate the pain for some patients, such as laying on their back with their hips and knees in a flexed position. If you are experiencing these symptoms, you should make an appointment with your doctor.
Back pain is present in many patients with lumbar disc herniations, but is not specific to this diagnosis and has many other possible causes. Back pain is highly prevalent in industrialized nations, and 80% of us will develop some degree of back pain at some point in our lives. In fact, back pain is one of the most common reasons that people see a doctor or miss work.
Rarely, a large lumbar disc herniation may cause an emergent scenario called Cauda Equina Syndrome. Patients with Cauda Equina Syndrome have a constellation of symptoms including bowel and bladder dysfunction (urinary retention), loss of sensation in the buttocks, groin and inner thighs (known as “saddle anesthesia”), and some combination of pain, weakness and numbness in the lower extremities. Cauda Equina Syndrome is a surgical emergency, and if you are having these symptoms, you should proceed to the emergency room.
I’ve been dealing with a back problem, and my doctor ordered an MRI of my lumbar spine. The report says that I have a disc protrusion. What does that mean?
Most patients these days have online access to their laboratory tests and imaging results through the medical record systems employed at hospitals, imaging centers and doctors’ offices. If you had an MRI of your lumbar spine and are awaiting a phone call or follow-up appointment to discuss the results, it can be anxiety provoking to read all the medical jargon that the radiologist has to say about your back.
The MRI does not make the diagnosis. Your doctor uses the findings on the MRI, in the context of the history you provided and their physical examination, to make the diagnosis.
It is important to know that many findings on MRIs are “incidental findings,” which means they may be normal age-related degenerative findings, or in some cases may be unrelated to the current problem that is being investigated. Several investigational studies have evaluated patients with no symptoms whatsoever and found that 30-40% of the patients had lumbar disc protrusions on their MRI.
What are the non-operative (conservative) treatment options, and how successful are they?
Physical therapy is an important component of non-operative treatment for lumbar disc herniation. Bedrest should be used for no more than a couple of days, as greater periods of inactivity can have a negative impact on the length of recovery and pain. Exercises that focus on core stabilization training with stretching and strengthening of the paraspinal muscles, combined with gluteal, hamstring and abdominal exercises, are usually warranted.
Because some patients have pre-existing back problems such as degenerative disc disease, arthritic pain in the joints of their spine and muscular pain, an experienced physical therapist can actively assess what exercises provoke pain and find a directional preference for exercises that patients can continue in a home-exercise program. Some therapists will use ultrasound treatment, electrical stimulation, and massage for symptomatic relief of associated back pain in the short term.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are first-line agents in treating the pain associated with lumbar disc herniation because an inflammatory reaction at the site of the disc herniation may be contributing to pain. Important issues should be considered when prescribing these medications, as they can have side effects.
NSAIDs may be contra-indicated in patients with a history of GI bleed or peptic ulcer disease. Some specific NSAIDs may have a lower risk profile for these patients. Patients taking certain blood thinner medications may be contraindicated from taking NSAIDs, as well as those with history of kidney disease. A tapering course of oral steroids may be helpful for the acute inflammatory pain of lumbar disc herniation as well.
When back and radiating buttock and leg pain is severe, short term use of narcotic pain medications in the acute setting of lumbar disc herniation may be considered. Preferably, these medications should be limited to just a few days at most.
Muscle relaxants or antispasmodic medications are sometimes prescribed for patients that have a significant component of back pain associated with muscle spasm.
Epidural Steroid Injections (ESIs) can provide symptomatic relief for many patients. ESIs are usually considered for patients who have failed the non-invasive treatments mentioned above, and are either not interested in having a surgery or are not an appropriate surgical candidate for some reason.
If a patient has more than one level of their spine with a disc herniation, an ESI can also help define or diagnose the symptomatic level. ESIs are typically done in procedure rooms, in the doctor’s office or at an ambulatory surgery center (ASC) under imaging guidance. Because of this, ESIs are not something patients should expect to happen their first appointment with a doctor for their disc herniation.
The reported success rate for non-operative conservative care of lumbar disc herniations varies widely, even amongst the industry’s best-designed studies. The good news is the vast majority of patients will achieve some degree of pain relief with the non-surgical treatments discussed above. Research that has looked at the long-term outcomes for patients treated non-operatively for lumbar disc herniation suggests 30-60% of patients had good results.
When is surgery for a disc herniation warranted?
Surgery for a lumbar disc herniation is called a discectomy. As stated earlier, a lumbar disc herniation that causes Cauda Equina Syndrome is a surgical emergency. Another indication for urgent discectomy surgery is when a patient has a significant or progressive neurologic deficit, or weakness in their lower extremity, that can be attributed to a disc herniation seen on imaging studies.
Most disc herniation surgeries are elective surgeries. This means they are surgeries that are scheduled in advance because they are not considered a medical emergency. The indications for elective discectomy surgery vary among surgeons and patients. Generally speaking, patients are a candidate for elective discectomy surgery if they have severe and disabling pain that is resistant to the conservative non-operative treatments discussed previously.
The timing of when this decision is made is variable. The surgeon needs to identify that the anticipated benefit of surgery outweighs the risks, and the patient will then be given all of the information they need to make an informed decision.
What does disc herniation surgery entail?
The two most common methods for lumbar discectomy surgery are a standard “open discectomy” and a minimally invasive (MIS) discectomy using special tubular retractors with the goal to make a smaller incision. Even with the “open” technique, the incision is usually approximately 1 inch long. In either case, the surgery usually involves removing a small amount of bone in the back, as well as an underlying ligament to access the place where the disc herniation is. The herniated disc material that is pressing on the spinal nerve and causing symptoms is then removed.
What are the risks?
Lumbar discectomy is one of the most common surgeries that spine surgeons perform and is generally considered low-risk. Most discectomy surgeries are done with general anesthesia, which is a risk common to any surgery. Unless surgery is an emergency, patients are required to have a pre-operative appointment with their primary care doctor to ensure that their overall medical health is not a contraindication to having general anesthesia and that they are medically optimized to proceed.
Any surgery has the risk of bleeding or infection, but the risk of clinically significant bleeding from a lumbar discectomy surgery is very rare. Infections have been reported in 1-3% of patients and many are minor infections near the skin level that can be treated with oral antibiotics and local wound care. Rarely a “deep” infection occurs that may require another operation to clean it out.
A tear of the dura (the sac that goes around the nerves) is reported in 0-4% of discectomy surgeries. If the dural tear is small and repairable, it usually doesn’t have any long-term change in the surgical outcome. Sometimes, patients may be kept in the hospital overnight on flat bedrest to prevent a spinal headache. A temporary or permanent nerve injury is also a very rare occurrence during surgery.
What should I expect in recovery?
Lumbar discectomy surgery is usually performed as an outpatient surgery, meaning patients go home the same day. Most patients will experience some, if not complete, immediate relief of the pain that was radiating into their leg. Some may experience “nerve pain” in the initial post-operative period due to inflammation from the surgery and retraction of the spinal nerve that was being compressed. Sometimes the sensation of numbness and tingling can persist for a longer period of time, and if patients have significant weakness before surgery, that can also take time to improve.
Post-operative activity protocols are surgeon-specific, but usually patients who have had a discectomy will have some sort of lifting restriction, limitations on how much they should bend or twist, and depending on their job or recreational activities, will have restrictions on when they can return to work or sports. Patients may also benefit from physical therapy after surgery at a time when it is deemed appropriate by their surgeon.
Patient-reported outcome data for lumbar discectomy tells us that one month after surgery, 99.24% of TCO patients report that they would have the surgery again, if needed.
-Dr. Kurt Duncan