In the previous columns we discussed episodic and chronic lower back pain (LBP) treated with non surgical means. I also briefly mentioned injections. The common name for them is “nerve blocks”; in reality this is a misnomer as there are many kinds of injections: injections in soft tissues; inside or around the spinal cord (epidurals and nerve root blocks) and through the small joints of the back. Specifically, the localized “freezing” sometimes injected inside the small joints of the spine called “facet joints” may temporarily take the pain away. Specialized doctors with the help of magnifying machines are able to “burn” the little nerves that go into these joints and render them “insensitive” to pain. This procedure called “percutaneous facet denervation” may relieve back pain for 1-5 years in a small number of patients who meet certain criteria.
When it comes to the treatment of Lower Back Pain with strong drugs, injections or surgery, are we doing any better today than we did 10 years ago?
A very recent study from the US (RA Deyo et al, J Am Board Fam Med. 22(1) 62-68, 2009) showed clear evidence that we do too much about LBP but gain very little. The researchers showed a 629% increase in Medicare expenses for epidural injections; a 423% increase in expenses for strong pain killers called opioids (like morphine and oxycontin); a 307% increase in the number of MRI tests for the spine; and a 220% increase in spinal fusion surgery rates. Despite this exuberant increase in tests, injections, strong drugs and surgeries, there is no proof that back pain occurs more often today than it did 10 years ago, nor that back pain sufferers are better after all these interventions.
But is there a role for actual surgery in back pain? There certainly is, in casea of seriously herniated and broken-up discs that pinche nerve roots or when excessive amounts of bone squeeze nerves (as in the case of spinal stenosis). In those situations the benefits of surgery are obvious and most people do well.
Unfortunately, back surgery is overrated patients frequently end up in continuous pain after an operation. In this case, they suffer from “failed back surgery syndrome” or FBSS for short, an all-inclusive term referring to persistent back pain after various treatments, usually one or more surgeries on the lumbosacral spine. There are different types of back surgery. Surgery in simple disc cases can be done through a small 2-3” opening in the back through which the surgeon removes the offending disc with a help of a microscope. In certain cases the surgeon needs a much larger opening and may use bone or hardware to stabilize the spine and the procedure becomes more complex. So, how often does one end up with FBSS after back surgery? The numbers are frightening. In the United States alone, more than 300,000 people’s backs are operated every year (more than in any other western country!) with 10-40% turning into FBSS. What accounts for such astonishing failures? Two respected scientists (one of them is a surgeon himself), Drs Anne Louise Oaklander and Richard North, list a number of reasons. Choosing the wrong patient or making the wrong diagnosis is the most common cause of failure, as less than 50% of those operated should not have been operated in the first place! Other causes for FBSS include permanent damage to the nerves of the spine by a herniated disc which pinched the nerves for long, incomplete surgery that did not manage to clean away the herniated disc, damage to the soft tissues, bones or nerves as a complication of the surgery and finally, formation of scar tissue or inflammation of the linings of the spinal cord (fibrosis or arachnoiditis). When FBSS occurs, most patients will need referral to a multidisciplinary pain program as they not only suffer physically but also mentally and emotionally.