SPINE SURGERY: When Is It Needed?

Brian W. Su, MD, and Robert H. Byers, MD

More U.S. health care dollars are spent treating back and neck pain than on almost any other medical condition. In 2005 alone, $86 billion was spent on the treatment of spinal diseases.¹ Low back pain is one of the most common reasons for doctor visits, with one in four adults in a recent survey1 reporting low back pain within the previous three months. neck pain is yet another common reason for these visits.

Effective management of spinal disorders can involve therapies ranging from conservative care to complex surgery. Conservative treatments include medication, physical therapy, acupuncture and chiropractic care. The next level of treatment is often injection therapy. Regardless of a patient’s spinal symptoms, the vast majority of patients can—and should—be treated with non-operative modalities.

Should all these treatments prove ineffective, however, surgery is sometimes an option. Surgical treatments can range from minimally invasive to extensive reconstruction of the spine. When indicated, surgery can have outstanding outcomes. Unfortunately, many patients are not good surgical candidates and are actually better served through ongoing pain management. Although we are surgeons, it is not uncommon for us to spend a significant amount of time talking patients out of spinal surgery.

For better or worse, the field of spinal surgery today is flooded with new technologies and experimental devices and techniques. Still, the best available evidence of treatment effectiveness is not through the advertisements or websites of these new technology providers, but rather through evidence-based medicine (EBM). The practice of EBM relies on the knowledgeable interpretation of results from clinical trials as reported in reputable peer-reviewed spine journals. One of our primary roles is to educate patients by presenting the results of these trials in a way that patients can understand. 

As a practice, we see thousands of patients and perform hundreds of spinal procedures each year. Based on this experience, what follows are our answers to the questions we are most often asked regarding care of the spine.

What can I do for initial onset back/neck pain before seeing a doctor?
Treat pain with rest, heat and/or ice, and anti-inflammatory medication. Over-the-counter medications include ibuprofen (Motrin, Advil), naproxen (Naprosyn, Aleve) and aspirin; acetaminophen (Tylenol) is less effective as it is not a true anti-inflammatory.

Regardless of which anti-inflammatory is used, it is important to build and maintain a constant baseline level of medication. This is accomplished by taking the medication around the clock every day for the first 14 days in a dosage dictated by either the package or your doctor. In other words, don’t make the common mistake of taking the medication only when pain occurs.

For low back pain, a soft lumbar corset/brace may be useful in the first week. Refraining from activities that make the pain worse—such as high intensity exercise—also typically helps during the acute phase of pain.

What can a primary care doctor do for a patient with spinal pain?
Most pain is categorized as either primarily “axial” (neck or back) or “radicular” (arm or leg). Acute axial spine pain is typically not from nerve or cord compression, but rather from injury to non-nerve tissue. Radicular pain is typically from a pinched nerve. It is important to understand that a pinched nerve in the back can cause buttock pain, just as a pinched nerve in the neck can cause pain behind the shoulder blade. Though pain in these areas is commonly mistaken as axial pain, it more often is caused by early nerve irritation and should be treated as such.

Axial pain treatment includes the use of prescription medications, physical therapy, acupuncture and chiropractic care. Commonly used medications include anti-inflammatories, muscle relaxants and narcotics. High-dose anti-inflammatories should be reserved for patients with no history of peptic ulcers or liver or kidney disease. If pain is associated with muscle spasms, cyclobenzaprine (Flexeril), baclofen (Lioresal) or diazepam (Valium) are often effective. Finally, narcotics can be used to diminish initially intense pain.

For radicular pain, steroids and/or medications affecting the nerves—such as gabapentin (Neurontin) or pregabalin (Lyrica)—may also be used. However, because these medications can have significant side effects, their benefit needs to be carefully balanced against their risks. Thankfully, their side effects are reversed once usage is stopped.

The use of oral steroids is indicated for severe pain only as they can cause avascular necrosis of the hip, a rare but catastrophic condition.² Physical therapy can be helpful once the initial pain is appropriately addressed. 

When should a patient seek the advice of a spine specialist?
Regardless of treatment, it is well established that 90% of spinal pain goes away within 90 days of onset.³ However, if a patient has persistent pain after six weeks of medical treatment, referral to a spine specialist is warranted.

Since nerves carry electrical signals to the arms and legs, a pinched nerve can cause not only pain but extremity weakness as well as numbness and tingling. Extremity weakness can range from barely noticeable to complete paralysis. For example, a pinched nerve at L5—the lowest lumbar vertebra—often leads to a foot drop as it can keep the muscle controlling the ankle from receiving adequate electrical signal. Typically, even with non-surgical treatment, as the nerve recovers, strength returns, but numbness and tingling may persist.⁴ Nonetheless, when radicular pain is accompanied by significant or progressive weakness, immediate referral to a spine specialist is recommended.

When should a patient be immediately referred to a spine specialist?
The spinal cord is essentially a continuation of the brain, sending and receiving signals to and from the entire body. It travels through the neck and thoracic spine and ends at the level of the belly button; from there, multiple nerves branch off, exiting the lumbar spine and sending signals to the bowels, bladder and legs. The multiple nerve branches in the lumbar spine are collectively named the cauda equina due to their resemblance to a horse’s tail.

There are two spinal conditions which, if left untreated, could lead to permanent neurological dysfunction: myelopathy and cauda equina syndrome.

Myelopathy is the clinical term for spinal cord compression in the neck due to age-related changes, disc herniation or trauma. Interestingly, patients with myelopathy do not always have neck pain. The symptoms of myelopathy are weakness in the arms or legs, hand/foot numbness, difficulty with bladder control, problems with balance while walking, and difficulties with fine manipulative tasks such as buttoning shirts and handling coins.

Cauda equina syndrome is the clinical term for compression of the nerves in the lower lumbar spine typically from a large disc herniation or trauma. It is unusual to see this syndrome with age-related changes of the lumbar spine. Symptoms include pain and weakness in the legs, numbness in the perianal area, and loss of bowel and bladder control. 

If a patient has symptoms of either myelopathy or cauda equina syndrome, an MRI should be ordered and the patient immediately referred to a spine specialist. An operation to take the pressure off the spinal cord or the nerves to the bowel and bladder is recommended sooner rather than later to prevent permanent damage.

Cauda equina syndrome is a surgical urgency, with best outcomes achieved when surgery is performed within 24–48 hours of onset.⁵

Unfortunately with these two conditions, despite surgery, most patients achieve stability rather than improvement in their condition.

What are injection options for treating spinal pain?
Spinal injections have long been a mainstay of spinal pain treatment. They are typically administered by physiatrists or interventional radiologists. Injections are generally categorized as an injection over either a nerve (epidural) or a structural portion of the spine.

With pinched nerves, epidural injections do not treat the mechanical cause of compression but rather decrease nerve inflammation, allowing the nerve to live in a reduced physical space. When compression is caused by a bone spur that is unlikely to resolve, the goal of the treatment is to enable the nerve to live comfortably in a reduced space once the injection addresses the inflammation. In the case of a soft disc herniation, the goal is for the injection to prevent nerve inflammation as the body heals the disc over time.

Several recent clinical trials have suggested that epidural steroid injections may be no more effective than the injection of local anesthetics.⁶  Subsequent criticisms of these studies have led to confusion for both patients and physicians regarding the true efficacy of epidural steroids.⁷ In general, epidural steroid injections have a 60% probability of working,⁸ providing pain relief lasting anywhere from a few days to several years. Since the risks associated with epidural steroid injections are low, we continue to use them as a first-line treatment for radicular pain that has failed medical management. Epidural injections are also used for diagnostic purposes. If medicine placed over a targeted nerve provides temporary relief, this tells us we will be addressing the proper area with surgery.

In the setting of radiculopathy (spinal nerve root dysfunction), we do not advocate repeated injections, particularly since steroid placed around the nerve has been found to cause loss of bone density.⁹ If patients need more than 2 or 3 injections for a structural problem (e.g., a pinched nerve), we encourage them to consider surgery to address the problem permanently.

How do I know if I am a good candidate for surgery? 
Other than for progressive myelopathy or cauda equina syndrome, every patient should first exhaust all non-operative treatment options and consider surgery only as a last resort. Even patients with pain and extremity weakness from a pinched nerve should be initially treated with conservative (i.e., non-surgical) care, as clinical outcome studies have shown that non-operative care leads to as much strength recovery as surgery. We typically tell patients that they should have surgery only if pain is interfering with their physical and emotional quality of life: physical quality of life meaning their ability to enjoy pleasurable activities (traveling, exercising, spending time with friends, etc.), and emotional quality of life meaning their ability to live without feeling depressed by pain.

In general, axial neck and back pain is multi-factorial and can come from a variety of anatomical structures in the spine. It is typically a combination of arthritis, disc disease and soft-tissue inflammation. For this reason, the diagnosis of axial pain is a trial-and-error process that can often be frustrating for patients. This is also why the treatment of axial pain should be non-surgical. While there are exceptions to the rule (such as for fractures or severe curvature of the spine), we generally do not recommend surgery for patients who have back pain alone, as it provides marginal benefit when compared to non-operative care.¹⁰ In fact, when 100 spine surgeons were asked if they would have spine surgery for axial low back pain alone, only 2 responded “Yes.”¹¹ On the other hand, patients with axial neck pain tend to be better candidates for surgery with an 80% chance of success.^12,13 Patients need to speak with a spine surgeon to carefully weigh the benefits and risks of surgery for axial neck or back pain.

Patients with back pain accompanied by buttock/leg pain or neck pain accompanied by shoulder blade/arm pain are good candidates for surgery because such pain can be traced to a specific problem: a pinched nerve. This, in turn, can be caused by specific conditions, including a bone spur, cyst, disc herniation, fracture or abnormal bone shifting (“instability”). With such an identifiable cause, surgical treatment has a greater chance of relieving extremity pain than non-operative care.^14,15 

In our practice, we spend a significant amount of time setting patient expectations for surgery, making certain that they understand that almost everyone who has spine surgery continues to live with some degree of residual pain. This is due both to chronic nerve damage that occurred prior to surgery and to other pain factors not addressed by the surgery. Spine surgery is often not meant to make patients 100% pain-free, but rather to make them feel markedly better than before.

I have never heard of anyone having a good result from spine surgery. How do I know what my chances of improving really are?
A key feature of our practice is the maintenance of a spine outcomes registry, a tracking of all of our surgical outcomes made possible by using standardized questionnaires. These outcomes are specific to neck or back surgery and are typically collected for clinical research on the effectiveness of spinal surgery.¹⁶ As an example, if the number 10 represents the most extreme pain a patient has ever felt, our registry tells us that the average patient experiences 7 (out of 10) leg pain before microdiscectomy surgery and 1.5 leg pain one year after. Also in our registry, when patients who previously had surgery for nerve compression are asked if they would have surgery for the same problem again, over 90% respond “Yes.”

We encourage all patients to ask surgeons what their surgical outcomes are. We believe it is unacceptable for a surgeon to tell a patient, “All my patients do well and have great outcomes.” Even in the best of hands, with perfect surgical indications, this simply cannot be true.

I heard that I should never have a spinal fusion because it means you have to keep having surgery at other levels. Is this true?
Typically, surgery to relieve nerve compression is performed minimally invasively, through a small incision. However, there are situations where taking pressure off the nerve is not sufficient to address pain and  weakness, and a more extensive surgery—such as a fusion—is required. This is particularly true in the setting of instability or for scoliosis (curvature of the spine) in order to provide mechanical stability to the spine. Furthermore, sometimes taking pressure off a nerve requires the removal of so much bone that it destabilizes the spine, thereby necessitating a fusion. When a fusion is required, multiple techniques are available. Your surgeon should be able to explain why you need a fusion, and only your surgeon can determine what the appropriate technique is for you.

The spine consists of bones that are sandwiched between discs that act as cushions. While fusing a few segments of the spine typically does not impact a patient’s flexibility, it can lead to increased stress on the segments above and below the fusion. This can lead to “adjacent level disease,” which occurs at a rate of 3% per year.^17,18 This means that 10 years after surgery, there is a 30% chance that there will be changes (visible on x-ray) at the level adjacent to the fusion. Note, however, that this does not necessarily mean that pain related to these changes will develop. Even though adjacent level disease has been attributed to fusion, disc replacements or other non-fusion techniques have not been shown to definitively decrease its rate of occurrence.^19,20 For this reason, some surgeons feel that adjacent level disease does not result from performing a fusion, but is rather a natural progression of disease.¹⁷ Most likely it is caused by both the increased stress from a fusion and the natural progression of age-related disc degeneration.

A recent large-scale clinical trial looking at the outcomes of lumbar fusion for a pinched nerve from instability in the back indicated outstanding outcomes up to even four years after surgery.^21,22 Overall, requiring subsequent surgery for adjacent level disease is an acceptable risk and is not a reason to avoid a fusion when one is indicated.

Am I a candidate for laser spine surgery?
Laser spine surgery treats spinal disorders by introducing a laser into the intervertebral disc through a needle or during open surgery in order to shrink the disc. The North American Spine Society, through its evidence-based committee, concluded that laser surgery in the spine cannot be endorsed as a surgical technique because there are no high-quality studies to support its use.²³ The Laser Spine Institute aggressively markets both the use of lasers as well as its ability to perform minimally invasive spine surgery.

While laser spine surgery lacks supporting evidence, minimally invasive spine surgery can lead to very good outcomes in the right patient. For this reason, it has been incorporated into surgical training and almost all spine surgeons are adept at performing these procedures. Only your spine surgeon can determine if you are a candidate for minimally invasive surgery.

Do I need spine surgery if my imaging studies show areas of degeneration and nerve/cord compression?
Patients often look at their x-ray or MRI report and conclude that surgery may be indicated to treat abnormal findings. As people age, discs and bones naturally undergo degenerative changes that, surprisingly, are often not a source of pain. A landmark MRI study found that over 90% of patients over 60 years old with no back pain had degenerative disc disease and disc protrusions.^24,25 Similarly, patients can have multiple areas of nerve compression that do not necessarily cause symptoms. It is up to your doctor to determine what the cause of your spinal pain is, as surgery is not always indicated for asymptomatic structural abnormalities seen on imaging studies.²⁶ The adage “We don’t treat the image, we treat the patient” holds particularly true for spinal surgery.

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Dr. Su, a fellowship-trained spine surgeon at Mt. Tam Orthopedics and Spine Center, is Director of Spinal Surgery at Marin General Hospital. Dr. Byers is a fellowship-trained spine surgeon at Mt. Tam Orthopedics and Spine Center with 20-plus years of experience. They can be reached at 415-927-5300 or www.mttamorthopedics.com.

References
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