Introduction
Disclaimer
Function, or a bit about how your back works
A Few Words About Pain
Common Threads in Spinal Surgery
DISCECTOMY
SPINAL STENOSIS SURGERY
FUSIONS
What, Again?
Future Stuff
Last Words
Links
Site Map
     
COMMON THREADS IN SPINAL SURGERY

 

Do you really need this operation?

There are very few situations where spinal surgery is really a burning emergency. Certain fracture and cancer cases apply, as well as some cases of disc hernia, but these are rare.

Most of the time spinal surgery is only an option and not a necessity in your care.

If your pain is very acute (you’ve only been sore for a short time), even if it’s very very bad, you’ll probably get better without surgery. If you’ve had your pain for longer and it’s not settling down, in most cases it’s not getting worse very fast either and you shouldn’t let anybody pressure you into the operating room.

You’re making an elective decision about an elective operation on yourself. It’s your decision to make and yours alone. You can get opinions and advice from professionals like me and from friends and loved ones, but only you can make the decision to go ahead. This should be an informed decision, so meet with your surgeon several times to talk it over if you’re not sure or unclear about something. Get a second opinion if you want it.

You should be 100% sure in your head and your heart that you want the surgery before going through with it. If you’re not, you shouldn’t have it done and a good surgeon will pick up on this and advise you against it.

Who should do it for you – or, operating may be a behavior too!

Spine surgery is a “growth industry” throughout most of the industrial world, with the number of surgeries being done every year going up all the time. Industry data suggests that about 750,000 surgeries were done in 1999 in the USA alone.

Some of the reason for this is the general ageing of the population. As people live longer their backs have more time to wear out and qualify for surgery.

Another reason is evolving surgical technology that lets we surgeons do more for our patients all the time, to treat conditions that were previously not treatable. There was a big increase in population rates of spine surgery in 1996 which gets debated a lot in the medical press where it’s argued that we’re doing too many operations now – but this corresponds very nicely to the introduction of “cage” implant technology that greatly expanded what we could do for our patients. Many of the surgeries that I do now hadn’t been conceived during my training.

Another difficult reason may be that, particularly in health-care systems with private-payment options, doctors are paid money to do it and just about every Tom, Dick and Harry who can will. That shouldn’t happen, but it does – all the time.

I vacationed in the Caribbean once and I have an old habit of looking at the Doctors’ ads in the Yellow pages when I’m away. Lots of cosmetic stuff down there, as you would expect. What freaked me out was liposuction. Not just dozens of qualified plastic and general surgeons doing it – but internists, pediatricians, dermatologists, all kinds of doctors who really have no business in an operating room!

The same thing may be happening, in a limited way, in spinal surgery today. As “minimally invasive” (read, “surgery without much cutting”) surgical technology develops, practitioners who don’t normally cut are increasingly trying to be spine surgeons. I read a case report of an internal medicine specialist who sucked out his patient’s nerve roots trying to do a minimally invasive discectomy one year. The editor of one of those expensive journals I read too much met an endocrinologist (that’s a medical doctor who specializes in treating hormone problems) at a spinal surgery course recently. Radiologists (X-ray doctors) are taking steps in this direction. Physiatrists (doctors who specialize in rehabilitation medicine) are being encouraged too.

Your surgeon, if he or she is smart, will want to check you out “up the kazoo” to be sure you’re the right person to operate on. You should similarly make sure that he or she is the right person to do it.

Are you dealing with an orthopedic surgeon or neurosurgeon? You should be.

Is your surgeon Board-Certified? He (or she; sorry, ladies!) should be.

Is he trained in spinal surgery? I don’t mean a few weekend courses. Many orthopedic and neurosurgeons aren’t. I, for example, was highly qualified with fractures and joint replacement surgery but barely saw a spinal operation (except for some fracture work) in the basic orthopedic training that lead to my Canadian and American Board certifications. I was legally allowed to and might have invited your back into my OR as a twice-Board-Certified surgeon when I was first licensed to practice without really knowing what I was up to at all. That’s why I starved my family and did a whole year of Fellowship training in spinal surgery before starting my own practice. Did your surgeon?

Has he done this operation before, or are you the first case?

How can you find out this stuff? For starters, you can ask. Most docs are happy to tell you about their training and experience (sure, we have egos). If there’s hesitation, be careful. Maybe ask for the 'phone numbers of a few patients who have had the surgery already, and talk to them personally.

Next, you can contact the relevant regional medical licensing authorities or medical associations directly. Most of these, as well as some doctors’ offices and many hospitals, have Websites that you can access too.

Lastly, remember second opinions? Get some. And you can ask for the scoop on your surgeon from another doctor just as much as you can ask for an opinion on your spine.

Will my pain relief from this surgery last forever?

Say it's six months after your surgery, or maybe a year. You're fully recovered and rehabilitated, you have no pain, you and your surgeon did a great job and you feel like a million bucks. You're going to feel like this forever, right?

Maybe.

Maybe? "What does he mean, maybe?" you're thinking? The problem's fixed, party's over, no problemo...!

Biology unfortunately is not that simple. Life goes on, things change. Let me explain a bit.

Have your appendix out. Once it's gone and the wounds are healed you can't get appendicitis again, no way no how. But you can get a surgically sore tummy! Some people have a structure in their gut called a Meckel's diverticulum that can get inflamed and mimic appendicitis very closely in its symptoms. And there's a condition of the large bowel called diverticulitis that is very common in middle-aged and older people which behaves very much like a left-sided appendicitis (your appendix is on the right side of your abdomen).

Better, have your gallbladder out. Once it's gone, it's gone, your gallstones should be a problem of the past, right? Most of the time that's very true, but there remain small channels in your liver that carry bile even after gallbladder removal and stones can form in them too.

Once your spinal problem is dealt with and you're fully recovered from the whole business, the emergence of another problem at the same level is very rare indeed though it can happen - we'll discuss it later, in the sections on the individual surgeries. But, the rest of your spine is still in there and you've declared yourself as one of those people who has already lost the race of the normal spinal degenerate balance once. Remember, symptomatic lumbar disc degeneration is primarily a genetically-based disease. You can get in trouble again. You might get another disc hernia someplace, or wear out another joint, and get in trouble a second time. Research suggests the odds are roughly 3% per year of life after critical symptoms - and having an operation doesn't change that! Several research papers now have followed surgical candidates who decided against the OR and sure enough, there was a 3% chance per year of life that something else would go wrong in their spines.

People like to blame this on the surgery, but we don't know that's true. When it happens right beside the surgical site some call it "adjacent segment disease" and the assumption is that the surgery has disturbed the neighboring joints. It may have and probably does, but that may not be the whole story.

We know a certain fraction of the population gets symptomatic spinal disease, right? We know very little about the odds of a second episode after your first has settled down without help from us, as is generally the case. In this situation, once the patient's gotten better they generally "go away" and follow-up research on this population beyond that point doesn't seem to happen.

But if that first or "index" episode was settled surgically we find there's a lot to read in the literature because we surgeons are writing up our cases and experience as we study our work all the time, and when we review those cases we encounter such people regularly. So there's a lot of data on the odds that "the surgery will go bad" and bring you back, and high-powered research going on in the attempt to develop surgical technologies that will avoid this.

This "going bad again", however, may be and probably is in fact just one more episode in what seems to be the relatively accelerated wearing-out of the spine in the surgical spine-pain patient. That's not your surgeon's fault, nor a failure of the operation. It's just another part of why you came to surgery in the first place.

Keeping your back healthy in the first place, or maybe the second

How can we keep the spinal surgical patient from getting in trouble again? Probably we can't, certainly we can't treat your genetics yet, but we'd like to try...

First, the surgeon can do his or her part by strictly limiting the extent of the surgery to that required to relieve the patient's pain. In English, I mean by doing only the minimum of cutting and dissection needed to accomplish the operation in the first place. This seems straightforward and it should be. It's what minimally invasive surgery is all about. Unfortunately this is not always practiced.

Can the patient do anything to avoid trouble? Maybe. Patients are forever asking what they might do to make the surgery heal better, take a vitamin or whatever. In most circumstances you can't do much on the positive side here, but there is often a lot you can do to make things go bad. I talked about this earlier in the section called "the two way street". Your odds will logically improve if you don't do those things.

Once you're fully recovered from your spinal operation, we can't change the wear-and-tear state of your spine but we may be able to affect the future evolution of your particular "spinal balance" through what we call "risk factor management".

Risk factors are basically things that increase the odds of something happening, but may not actually be causing it. When medicine doesn't understand a disease process well enough to treat it directly, we try to help our patients by identifying those risk factors and getting them out of your life. An example might have been our advising diabetics not to eat sugar back before insulin was discovered. Sugar doesn't cause the high blood sugar levels in diabetes, a lack of insulin does, but back then we didn't know it.

There are really only five things that are well-identified (read, scientifically proven) as "risk factors" for symptomatic premature degenerative spine disease. These are obesity, certain types of heavy physical work, heavy motor vibrations, smoking and stress. I think they all wreck your balance.

Earlier in Section One I described the normal spinal degenerate balance between the fact of everyone's spine starting to "wear out with time" in their 20's and those worn-out discs and joints being replaced with strong scar tissue and bone spurs as we get older. Remember? Think of "stuff wearing out" versus "stuff scarring in".

Being massively overweight would obviously tend to accelerate the "wear and tear" side of your balance. I think that being terribly out of shape does the same thing. If your back muscles are very weak they won't be able to take much load and more will rest on your discs.

Jobs involving regular heavy lifting and bending have long been recognized as associated with back and spine pain problems. Wear and tear are increased here again. I think twisting belongs here too, since biomechanical analysis suggests that the load on your discs just about quadruples with twisting. I also think that the word here should be "activities" rather than "jobs". Certain sports like American football (linebackers), rowing and gymnastics also seem to bring people to spine surgeons a lot.

Heavy motor vibrations (like a diesel engine, or possibly a Harley) are bad news too. They also act on the "wear and tear" side of your balance. Here's how. Any structure can be made to vibrate or wiggle a bit. You wiggle the Jello™ on your spoon (c'mon, admit it!). Play with it a bit and you'll find you can get the Jello™ shaking all over with just a little wobble in your wrist. That defines something called the "resonant frequency" of Jello™. Your spine has two different resonant frequencies, and they are very close to the "thrum, thrum" sound of a heavy motor. That rumbling Harley or your semi is beaming energy straight into your low back and shaking it apart! I see lots of truckers and bikers in my office.

On the "stuff scarring in" side of your balance, research suggests that smokers are several times more likely across the board to develop structural spine disease than are people who don't smoke. This is a very controversial statement where the science is fuzzy, but the stuff does cause cancer too! Smoking seems generally to decrease your body's ability to heal. A smoker's cut gets infected more often, wounds and broken bones heal more slowly, your blood clots more often to cause a stroke or a heart attack. If you can't heal well, you won't scar in fast either and it seems you're more likely to loose the balance race in your spine.

Lastly, stress. Why stress? Being stressed changes the hormone levels in your body, and certain hormones (the steroids) are very bad things for wound healing indeed.  It seems those subtle hormone changes in stressed people can make all the difference to your spine in the long run, by cutting back on your body's healing potential. So chill out!

What about risk?

Surgery can be a risky business, no doubt about it. There’s upside risk (the odds that your spine operation will relieve your pain) and downside risk (some chance that bad things might happen), as well as some chance your pain might not be relieved and the operation won’t change things at all for you. Fortunately the odds are generally pretty good that you’ll get through it all and be better off for it. If that weren’t the case, people like me would be out of a job!

When you sign that consent form, you’re accepting those risks! Your surgeon and the rest of the surgical team will do their best, but nothing is perfect in biology and things can and do go wrong. If things could be guaranteed, Midas Muffler wouldn’t need one. Don’t see a surgical complication as money in the bank from your lawyer, because when you signed up you effectively said “Yes, Doc, go ahead!”

It’s probably impossible to list off every possible complication that can occur around an operation, so don’t expect me to be perfect and hit every nail here. I’m just doing my best.

I like to think of risk categories. First there’s the chance or “risk” that the surgery might not relieve your pain. Then there are the risks of the anesthetic, the general risks of having an operation, risks that relate to lying on your tummy (we call this the “prone” position) for sometimes several hours while the surgery is being done (more soon, this is a big deal), general risks in having somebody work on your back (let’s call these “risks of the surgical approach”), the risk of complications specific to the major categories of operation and lastly the risk or chance of needing another operation in the future.

The exact and specific risks to each particular operation are probably best discussed in the section on that operation, so that’s where you’ll find them. As to the rest, here goes!

Risks of having an anesthetic

Going under a general anesthetic is a major thing. Your muscles are chemically paralyzed, your body’s ability to control your blood pressure and heart rate and temperature are all gone, those machines and the anesthetist are literally keeping you alive. Don’t take it lightly. If even one little piece of equipment doesn’t work right, or if you have some sort of drug reaction, it can cost you your life.

In Canada, I’m told the risk of death from an anesthetic is about 1 in 70,000 operations. That’s not 1 in 70,000 people . Having gone to sleep before does not change that number, it’s a risk in every operation you have.

This risk may vary a bit depending on where in the world you’re having your surgery.

It will also vary with your general medical condition. The older and sicker you are, the riskier surgery becomes. An internist can check you out before surgery and give you odds specific to your health status.

There may be things worse than death. If the life-sustaining drugs and machinery don’t work exactly right, you might not die but just run a very low blood pressure or blood oxygen level during the surgery. When that happens (really really rare, thank God!) the patient wakes up with the equivalent of a stroke. What’s a stroke? Brain damage, with variable results ranging from being a bit loopy to partial paralysis to drooling in a wheelchair and a diaper at the nursing home for the rest of your life. Yes, that really happens. A famous pioneer spine surgeon had hip replacement surgery some years ago and apparently woke up without most of his marbles, so to speak. End of career, effectively end of life as he had trouble recognizing his family. It could happen to you too.

The media always glorify the surgeon. Your anesthetist is just as important to you, if not more so.

Now just for interest, let me tell you that it is actually possible to do many spine operations without putting you to sleep! This can involve either a regional or local anesthetic technique.

Why on Earth would someone consider such a thing?

A regional anesthetic involves having one region or part of the body anesthetized or “frozen”. Moms go through this when an epidural needle in their low backs freezes everything from the waist down for childbirth. We can do the same thing for some spinal surgery. It’s often uncomfortable for the patient and stressful for the anesthetist, but the advantage is that the patient is breathing for him/herself during the surgery. You might be awake, or you might go to sleep. The stress on your metabolism generally is decreased, and people with bad lungs or heart disease in particular might be offered their surgery this way.

A local anesthetic is just what it sounds like, dental-type freezing injected around the incision site just before we cut. This is quite rare. The advantage is that the underlying spinal cord and nerve roots are not frozen, so if they are irritated during the operation the patient can tell the surgeon and help keep the procedure safer. I’ve actually done it about six times, in cases of difficult neck injuries where we were worried we might squish the spinal cord when we were putting dislocated neck bones back in place. It’s hell for all parties involved, but can be an important option in certain cases.

General risks in having an operation

Surgery almost always involves an incision of some sort, the “cut”. Often in spine surgery we have to make two or more incisions in one case. Any cut can get infected, right? Yes. Even with intravenous antibiotics given before, during and for a variable time after surgery the risk is at least about 1% in spine surgery.

There are two types of incision-related or “wound” infections in spine surgery, superficial and deep.

Superficial wound infections are basically infections in the healing skin around

the cut. These are by far the most common, occurring in about 1% of cases. They show up within days or sometimes weeks after the surgery as a red tender swelling with local pain but not usually any fever or pus. Some antibiotic pills and local wound care just about always settle things within a week or two. Once settled, they’re gone.

Deep wound infections are much more rare (roughly 1/600) but they can be a real problem. They seem to happen most often in obese older patients having major spine surgery with implants and bone grafting, though diabetes may be a risk factor as well. They show up some months after surgery. They might be very low-key or “low grade”; perhaps the patient has some pain and scans confirm an infection. They can also be more aggressive, as red swellings or “boils” forms close to the incision and rupture to discharge pus, bits of bone graft, loose screws and God knows what else.

With a low-grade infection, simple antibiotic tablets may settle things down though you may have to take them for months. However, a higher-grade or more aggressive deep wound infection often means you’re going back into the operating room so the wound can be opened and cleaned out. Depending on the extent of the infection, this may need be done several times before things settle down. Infected hardware or bone graft might need to be removed. You might need another reconstructive operation once the infection settles down. Not fun for anybody.

When you’re injured (and an operation is, after all, a type of injury) your blood thickens up a bit to minimize bleeding. Doctors call this the “hypercoagulable state” (Gesundeheit!). Makes sense, no? But, if your not up and around, that thickened blood tends to clot off in the big veins of your legs (“thrombosis”, or “DVT”) and bits of those clots can break off (“embolize”) and wander through the bloodstream to important places like the brain (causing stroke), heart (heart attack) or lungs (embolism). It’s what “economy class syndrome” in air travel is all about. This again is very rare in spine surgery. I can remember three cases from my practice in twelve years. We can fight it both by giving you blood thinners for a few days right after surgery and by doing the operations in such a way that you can generally be up on your feet so the blood circulates out of your legs the day after the surgery.

What about bleeding, and transfusion? While some spine surgery like discectomy can be done with only a few drops of blood loss, some big reconstructive fusion cases can bleed more than the patient’s body holds in the first place. Some of this risk relates to your size, the bigger you are the more cutting we have to do and the more you’re going to bleed. Your surgeon should be able to eyeball the risk needing a transfusion in your procedure for you.

In this day and age (the 2000’s), the risk of having an allergic-type transfusion reaction or getting something like AIDS or hepatitis from screened volunteer donor blood is negligible, just about the same as the risk of getting those diseases from the blood of your own family members. If your hospital uses blood or blood products from paid donors, the risk will be higher.

The best way to avoid all this is to avoid the transfusion in the first place. How to do that? One way is to let the patient get good and anemic (watch the blood counts drop) after surgery, and we do, but there’s a limit as to how thinned-out your blood can safely get. Let’s consider options before, during and after the surgery.

Before surgery, you can donate your own blood to the bank so you get your own back. The most you can produce safely is three or sometimes four units, enough to replace moderate blood loss or deal with “medium-sized” surgery. However, doing this means coming into the OR weakened from blood loss and with a lowered blood count that gets we doctors thinking about transfusing you earlier than we might have otherwise. And when we give you your own blood back off the shelf, it’s not very healthy stuff. We can only store your red blood cells , so the serum and other good stuff in there is separated out before storage and you don’t get it back. Also, the lifespan of a red blood cell is measured in weeks, so that stuff you put on the shelf is half dead before we give it back. Great, huh?

Another nice option here are drugs called “erythropoetins”, basically the cloned hormone that tells your body “make blood now”. These involve weekly injections costing roughly $(CAN)500 a shot given for a month (four weeks in an average month, that’s four shots) before the surgery, so you come into the OR with an artificially elevated blood count and can afford to safely loose more of it. They’re not for everybody, high blood pressure or a history of stroke make this unsafe, but it’s a nice option if you can afford it.

Maybe the best bet before surgery would be to combine using erythropoetins with a bank-your-own-blood program. Fire up your blood count, then draw off just enough to make you “normal” and put that blood on the shelf, and then dive right into the operation!

During surgery we can do several neat things, of which I’ll describe what I think are the three most common. One is called an “intra-operative phlebotomy”, where we basically hook up one of your IV’s to an empty blood bag at the start of the case and drop that bag on the floor so that blood from your IV can drain into it. We’ll fill two or three bags, giving you saline solution as the blood comes out to keep things even. During the surgery you lose correspondingly thinned blood, and then at the end of the case we run what we bled off back in. This is a really great technique. Quick (we do it in the OR after you’re asleep so it really takes no extra time at all), safe (you’re getting your own blood, and there’s no risk from exposure to drugs), cheap (a blood transfusion bag costs just a few dollars, there are no blood storage and shipping costs, and again there are no drug costs involved), no fuss (no running back and forth from your doctor’s office for injections and blood counts, no traveling to the blood bank,) and bother, and you the patient are getting your own fresh whole healthy blood back. Again, this is a technique good for moderate blood loss.

For bigger cases we can use machines called “Cell Savers™ ” [this is actually a trade name]. These are suction machines that take the blood lost at surgery, wash the cells and let us give a good portion of them back. This is a nice option in major spine surgery. You need about half a liter (call it a pint) of blood loss just to fill up the machine and get it running.

The last “during the surgery” option I’ll describe involves having the anesthetist give you an infusion of clot-thickening drugs called “antifibrinolytics” during the operation. If we can thicken your blood the surgical cuts might bleed less during the surgery, no? These drugs are standard practice in cardiovascular surgery and there is good data to support them in hip and knee replacement as well as scoliosis surgery, and I’m building some data that may prove them helpful in spine cancer surgery too. As yet they’re unproven for reconstructive spine surgery but I know what I’ll want when my time comes....

After the surgery, we usually put a suction drainage system of some sort into the wound to remove postoperative bleeding that might form a hematoma. There are wound drains available with filters on them such that once they fill up we can hook them back to your IV and give the shed blood back. They’re good for about a unit and a half of blood.

Another risk of surgery is pain. We cut you, you’re going to hurt.

Surgical pain seems to have three phases. You’re really hurting for two or three days and will need serious and regular pain medication, often narcotics like morphine, for this time. Then, all of a sudden the severity of the pain seems to be cut just about in half as your body’s healing seems to catch up to the surgical injury and you’ll want to get up and start moving around. Ladies do hair and makeup, guys shave. Later again, around three to four weeks after surgery, the severity is cut in half again as the pain of the incision is just about gone and all that’s left is the deep healing pain inside that fades progressively over another few months. Oh, yes, I forgot to ask. Were you hurting real bad and on narcotics for a long time before the operation? If so, your system literally can “get used to the drugs” even if you’re not addicted and you may have trouble with pain control after the surgery because of it. Don’t be embarrassed and please be honest, tell your surgeon and the pain-control team what you’ve been using so we better help you with pain control after the surgery.

Modern pain control techniques are really effective. We can’t make your pain actually go away short of putting you back you sleep, but things like PCA machines and indwelling epidurals (your surgeon will discuss these with you, depending on availability) can take just about all the bite out of the first few days. After that, you’re laughing.

Another risk is the possibility of chest and breathing problems. The physiology of our lungs is such that they are basically designed to build up phlegm and collapse. We normally prevent that by taking occasional deep breaths, sighing or coughing every so often. During surgery we can’t do those things and phlegm builds up. After surgery it may hurt to cough so we can’t clear our chests. Put it all together and you get pneumonia, infection in the lungs. This is bad news, the patient is sick with a high fever. Every time the pneumonia patient coughs it hurts, in the chest and at the surgery site. These infections can still go uncontrolled and cause death even in this day and age. We try to prevent this by sending a physiotherapist to help you cough after surgery, and sometimes use other breathing techniques and medicines similar to those used to treat asthma.

Next is the possibility of your having trouble peeing. While enough nerve damage to knock out your bladder just about never happens, trouble passing urine is quite common in the first few days after spine surgery. Pain and drug side-effects account for it. We treat it by keeping your bladder empty and its muscle tone up with catheters. Yuck. If I’m the patient, I really don’t want to know about these. That’s why I put my own patients’ catheters in in the OR, once they’re asleep. Ask your surgeon for this kindness. We can also help here by getting you up and around fast. Ever try to pee lying down in bed, or on a bedpan? Not for me!

Still among the general risks of surgery are stress-related illnesses like bleeding ulcer or a gallbladder attack. Many surgeons regularly give medicines to prevent these nowadays and they’re generally history, but you the patient can help us out. If your ulcer flares up in the week before your spine surgery is scheduled, call up your surgeon and perhaps it might be wise to delay things a bit.

Risks of the prone position for spinal surgery

“Prone” means lying on your tummy. Obviously, in spinal surgery you’re positioned that way so we surgeons can work on your back without standing on our heads. So what’s the big deal, you ask?

One issue is that whole question of skin pressure and the possibility of ulcers. You’ve heard of paralyzed people who can’t feel their legs, or diabetics whose nerves have been numbed by excess blood sugar, getting ulcers, no? Our skin is very sensitive to pressure. Only 32mmHg, much less than you create in pinching your fingertips together, is enough to cut off the flow of blood in your skin. That’s why your fingertips turn white or “blanch” when you make a pinch. Stay pinched long enough and your fingertip will start to hurt from lack of blood. A bit longer and your fingertip will turn black and fall off.

Sitting or lying down easily puts enough pressure on our skin to cut off the flow of blood. Normally, when we’re sitting for a while or even when we’re asleep, we “fidget” every so often to shift the pressure areas around and keep our skin healthy. Under an anesthetic we can’t do that. While lying prone the pressure runs high in several skin areas.

Your eyes are very sensitive to pressure like this. It’s not hard to lie a patient prone with enough pressure on the eyeballs to cut off the flow of blood. PEOPLE GO BLIND FROM SPINAL SURGERY BECAUSE OF THIS – one or two a year in North America, give or take. That’s one of the risks of spine surgery. It’s one that’s almost never discussed, and it should be. I’m as guilty as any of not usually remembering to mention this.

The nerves in your arms and legs are sensitive to pressure like this. It’s not uncommon to wake up with some numbness in an arm or leg from it. Fortunately it’s usually very temporary and usually gets better within a few days, or weeks.

In spine surgery, for complicated technical reasons we try really hard to get all the pressure off your abdomen (your tummy, or a man’s “gut”) when you’re positioned for surgery. There are some operating tables that flex your hips and knees to do that, effectively putting you in a “hands and knees” position during the operation. This can put tremendous pressure on your shins, enough to cut off the flow of blood there too. Amputation of the leg is another rare but recognized possible complication of spine surgery!

If you’re really heavy, lying on your tummy forces your abdomen up under your diaphragm (breathing muscle) and into your chest. This can force the breathing machines to work at a very high pressure, enough in a severe case to collapse the lung or sometimes creating a situation where we just can’t breath for you and have to flip you over, wake you up and cancel the surgery. I’ve had to do that twice in my practice.

All of these problems could be avoided by positioning you otherwise. It is technically possible to do spine surgery with the patient lying on their side, but that’s not a part of regular surgical practice or training and very few people in the world can do it competently.

Risks of Approach – Posterior Surgery

Posterior surgery means “operating on your back from the back ”.

First, we have to dissect all your back muscles to get to your spine. That causes some muscle damage with potential for scarring and loss of strength, but usually not enough to be a problem.

Next, we’re working all around the spinal cord and nerve roots with aggressive surgical instruments that are designed to cut stuff. Slipups can be a problem, or say a piece of worn-out surgical equipment breaks. I’ve had as many as six overworked surgical instruments fall apart in my hands during one operation in Canada. Worst case scenario, if all that neurological stuff were cut or torn you could be paralyzed. That means living in a wheelchair and a diaper for the rest of your life, and maybe no more nookie! The odds of neurological catastrophe like this are slim, probably somewhere around 1/100,000. That’s about the same as the risk of dying from your anesthetic, so you can put it in perspective that way. If you’re not too worried about the one, don’t worry about the other – but either can happen, and when you sign up you accept that risk.

If your operation involves the insertion of a spinal implant system of screws and whatnot, there’s always a chance a screw might wander out of ideal position and irritate a nerve root. Or, a screw might break. This sounds horrible, but just about all broken and most misplaced screws in fact don’t cause any symptoms at all. When they do you’re generally looking at some minor weakness and/or numbness in one of your legs, not a crippling catastrophe at all. Odds are about 1% in capable hands.

If your operation involves the surgeon working within the disc, either to remove part of it or to do a fusion there, we have to consider the risk of damage to blood vessels. Your discs are very small, only about an inch in diameter tops. It’s not hard to imagine how, working from your back with little tools and scrapers and such, we could poke an instrument out the front of your disc. Right in front of your discs are some of the largest blood vessels in your body. If they’re damaged it can cause catastrophic bleeding into your abdomen, like a ruptured aneurysm, such that we need to flip you over right away and open up your tummy from stem to gizzard to get control of the bleeding and save your life. This is a rare event, happening about once every five years in Ontario (our population is a bit over ten million people), but whenever it does happen there seems to be a lawyer under every rock in about two seconds! I warn all my patients about it, and I’m telling you here too.

Risks of Approach – Anterior Surgery

Sometimes we have to operate of the front part of your spine directly, by going through your chest or abdomen. Certain fractures, tumors and deformity cases are the common reasons, but we do some fusions and all disc replacement work this was.

On the sides of your vertebral body lies a network of small nerves called the “autonomic” (also “sympathetic” or “parasympathetic”) nerves that are involved with automatic body control functions like directing blood flow and temperature. Whenever we do anterior spine surgery, we dissect out these nerves somewhat and they can be damaged. If that happens, you can end up with a “sympathectomized” leg that has increased blood flow, warmth and a tendency to swell. Odds are probably about 1 in 3. Fortunately, this effect just about always resolves itself over six months or so.

Going through your chest when we are up there, the small nerves of your rib cage are easily damaged and that can cause extreme pain along the scar, the “post-thoracotomy syndrome”. This can hurt more than the back problem did in the first place. With modern technique it’s rare, but it’s a disaster when it happens. However, it is probably fair to say generally that anterior incisions tend to hurt more and longer than posterior ones.

You’d think that lung damage would be a big deal here, but it’s very rare.

Remember those big blood vessels that we can damage when we’re working through your disc space? We’re looking right at them when we “go from the front”, either in the chest or the abdomen. Significant damage is rare, but it can be disastrous – you could bleed to death, or loose a leg. Hugely rare, I can’t suggest numbers, but yes it’s happened.

Working through your abdomen, we have to cut through a lot of muscle to get there in the first place. The ensuing muscle weakness can cause hernias and whatnot, sometimes needing surgical repair. This too is rare with modern technique.

The sympathetic nerves and big blood vessels are right there in your abdomen, just like they are in the chest. Same risk.

HERE’S A BIG ONE! In men, some of the autonomic nerves controlling sexual function are right in front of the lower spine and can be easily damaged surgically. When that happens it causes “retrograde ejaculation”. A fellow can still function and have fun but the system “backfires” and sperm don’t come out. Conceiving children will require medical assistance. Risk is limited to surgeries at the very lowest levels of the low back, particularly L5/S1, and is something around 1%.

Lastly, in anterior spine surgery we frequently insert implants called “cages” or artificial disc replacement devices into the disc space. Technical errors here can make the things push disc material onto the nerve roots (causing sciatica). Also, they can jump out of position easily to squish spinal cords and blood vessels. All of these are rare, but they can mean repeat surgery.

The Risk of Needing Another Operation in the Future

Nothing can be guaranteed in life.

With modern diagnostics, technique and surgical technology we can just about always figure out and fix your structural back pain problem, but we can't change the fact that you the patient have a spine that wore out prematurely in the first place. That spine has been "out of balance", degenerating faster that it could heal, for a long time. You may have trouble again in your future, no matter how well your surgery goes.

What are the odds? That depends. Here are some snapshots.

If you've had a discectomy, there's a 6%-7% chance that another herniation of the same disc could happen somewhere in your future, generally within a year or two of your surgery. We can't predict or prevent it in a given case.

If you've had a laminectomy, literature suggests it's 50/50 you'll need something more done within five years and there's a 90% chance the darn thing will significantly regenerate in ten years! Usually this is without symptoms, but not always.

If you've had a fusion, there's a minimum 1%-5% chance that it won't knit and we have to do it all over again. In many circumstances there's a 30% chance that even a solid fusion won't take your pain away!

If you've had a fusion, it's almost 50/50 that your X-rays will show accelerated degeneration of the discs above the fusion site at ten years, and a 15% chance that you'll have pain and possibly need more surgery because of it.

If you've had a fusion with implants (pedicle screws), there's a 1 in 4 or 5 chance that the darn screws will hurt enough that they'll need to come out. That happens two or three years postop. Taking 'em out means a routine day-surgical operation in my practice, but it will still slow you down for about two months.

Beyond that, remember disc degeneration is a genetic disease, so 3% chance per year of life that something else will go wrong in your spine.....

What can you the patient do to minimize all this risk? No, there's no special pill or vitamin that "would make it heal better".

One important thing to do is follow your surgeon's instructions to the letter. In practice one finds that patients are always running off to their family doctors, therapists and friends for advice, following their often inappropriate if well-intentioned instructions, and screwing things up royally. Sorry to be impolite, but there's no better way to say what I mean. For at least the first six months or so after the operation, your surgeon should be just about at the right hand of God in giving you instructions about care, activity and therapy. No one else matters!   Sure, most of us aren't always reachable at a moment's notice - but we all have office staff and pagers and answering services that can connect us to you within a few hours or so, so call and ask if you're not sure about something.

Another important thing to consider is controlling those risk factors that increase the odds of your back going bad in the first place. We haven't yet been able to prove this works with back patients, but it's safe and simple and generally inexpensive and sure makes good sense!

Risk factors are basically things that increase the odds of something happening, but may not actually be causing it. When medicine doesn't understand a disease process well enough to treat it directly, we try to help our patients by identifying those risk factors and getting them out of your life. An example might have been our advising diabetics not to eat sugar back before insulin was discovered. Sugar doesn't cause the high blood sugar levels in diabetes, a lack of insulin does.

There are really only five things that are well-identified as "risk factors" for symptomatic premature degenerative spine disease. There are obesity, certain types of heavy physical work, heavy motor vibrations, smoking and stress. I think they wreck your balance.

Earlier in Section One I described the normal spinal degenerate balance between the fact of everyone's spine starting to "wear out with time" in our 20's and those worn-out discs and joints being replaced with strong scar tissue and bone spurs as we get older. Remember? Think of "stuff wearing out" versus "stuff scarring in".

Being massively overweight would obviously tend to accelerate the "wear and tear" side of your balance. I think that being terribly out of shape does the same thing. If your back muscles are very weak they won't be able to take much load and more will rest on your discs. So thin down, and get in shape!

Jobs involving regular heavy lifting and bending have long been recognized as associated with back and spine pain problems. Wear and tear are increased here again. I think twisting belongs here too, since biomechanical analysis suggests that the load on your discs just about quadruples with twisting. I also think that the word here should be "activities" rather than "jobs". Certain sports like American football (linebackers), rowing and gymnastics also seem to bring people to spine surgeons a lot.

Heavy motor vibrations (like a diesel engine, or a Harley) are bad news too. They also act on the "wear and tear" side of your balance. Here's how. Any structure can be made to vibrate or wiggle a bit. You wiggle the Jello(TM) on your spoon (c'mon, admit it!). Play with it a bit and you'll find you can get the Jello(TM) shaking all over with just a little wobble in your wrist. That defines something called the "resonant frequency" of Jello(TM). Your spine has two different resonant frequencies, and they are very close to the "thrum, thrum" sound of a heavy motor. That purring Harley or your semi is beaming energy straight into your low back and shaking your spine apart. I see lots of truckers and bikers in my office!

On the "stuff scarring in" side of your balance, research suggests that smokers are several times more likely than nonsmokers to develop structural spine disease. This is a very controversial statement where the science is fuzzy and indefinite, but the stuff does cause cancer too! Smoking seems generally to decrease your body's ability to heal. A smoker's cut gets infected more often, wounds and broken bones heal more slowly (the chance of a wound healing problem after spine surgery in a smoker has been shown to be ten times higher than in nonsmokers), your blood clots more often to cause a stroke or a heart attack. If you can't heal well, you won't scar in fast either and it seems you're more likely to loose the balance race here.

Lastly, stress. Why stress? Being stressed changes the hormone levels in your body, and certain hormones (the steroids) are very bad things for wound healing indeed. It seems those subtle hormone changes in stressed people can make all the difference to your spine in the long run, by cutting back on your body's healing potential. So chill out!

 
         
<To Top>