Why patients don’t get better after spinal surgery (it’s not always my fault.)

Ok.  I’m going to admit this for you right here and right now: my patients don’t always get better after surgery.  It’s a crazy thought, I know.  But it’s true.  Despite my best efforts to control all variables to ensure that things go smoothly, things can go awry and the patient doesn’t get better (and sometimes gets worse).  Generally speaking there are two categories of variables that must be managed to ensure success in spine surgery.  First, there are the variables that are dependent on me, the surgeon.  These variables stem from the technical, physical and psychological challenges of spine surgery.  I have to correctly diagnose the patient; I have to know the anatomy and technical nuances of the surgical procedure; I have to plan for the patient-specific anatomy of the case; I have to get a good night sleep before my OR day so that I can focus on the case; I have to maintain a level of fitness in order to handle the physical demands of surgery (yes, spine surgery can be quite physically taxing), etc.  No problem.  This is what I signed up for and I’m up for the challenge.  I can manage these variables better than most.  I do want to say one thing about the psychological stress of these cases.  I want every one of my patients to have the best possible outcome.  That itself weighs on my psyche enough.  But when things don’t go as planned and a patient has a poor outcome (I feel as if I hurt them) it can take months for my conscience and confidence to recover.   This isn’t a therapy session though.  I love what I do and overall I think that I handle the stress of it pretty well (my wife is blocked from posting comments on Spinal (con)Fusion, by the way.) 

Here’s what drives me crazy about taking care of spine patients though.  I can control all of the variables on my end and execute perfectly and the patient STILL doesn’t get better.  There isn’t always a direct correlation with my success in the OR and the patient’s outcome.  Why?  Patient-dependent variables, which often are out of my control, also affect outcomes in spine surgery.   Here, I offer a few of the ways patients don’t hold up their end of the doctor-patient relationship.

1)  Patients don’t want to get better.  Ok, so this is a very broad and potentially very damning characterization of some patients.   You could say obese patients or smokers don’t have the discipline to better themselves and thus don’t want to maximize their chances of success after spinal surgery.  As tempting as it is, though, we can’t blame patients for being obese or for smoking.  Both of these are diseases that many patients are incapable of managing on their own.  So while I do think patients in this country should take more responsibility for their own health, we shouldn’t automatically assume that they don’t want to get better because of their weight or their bad habits.    

What I’m referring to here is a more pernicious subset of patients who are actively trying to not get better, the landmines in the minefield that is my clinic.  These patients usually have some sort of secondary gain that they’re after that leads them to consciously or subconsciously fail to improve after surgery.  Maybe they were injured on the job and want to live off of a worker’s compensation claim.  Maybe they don’t want to be in the military anymore.  Maybe they were in a car accident (not their fault) and their lawyer is telling them they can get more money if they appear more severely injured.  Maybe they want more attention from their spouse.  Maybe they just want oxycodone.  You wouldn’t believe what I’ve seen.   And before you come after me for being insensitive, check the literature.  There are dozens of studies correlating secondary gain with poor outcomes in spine surgery. Thankfully as I’ve moved along in my career I’ve gotten better at spotting patients like these and will avoid ever offering them surgery.  That’s the art of spine surgery.

2)  We aren’t good at accurately measuring if a patient is in fact better.  In spine surgery we rely on patient reported outcomes (PROs) measured before and after surgery to assess the patient’s response to the surgery.    PROs generally fall into two categories: those that measure pain severity and those that measure level of disability.   The visual analog scale (VAS) is the most common tool used to assess a patient’s pain level (see figure 1).  In this scale the patient is asked to rate their back or leg pain on an 11-point scale where 0 is no pain and 10 is the worst pain imaginable.  While VAS is useful on a superficial scale, I find that patients’ responses are widely variable thus making the test unreliable.  I frequently will see that a patient has rated their pain a 10/10 on their intake paperwork but when I walk into the exam room they’re sitting comfortably reading a book.  If this is how the patient self-assesses their pain how can I know for sure that the patient in fact got better?  The problem is that pain is so subjective and influenced by so many factors that it’s just hard to quantify objectively.     

NewImage

Figure 1: Visual Analog Scale (VAS) for reporting pain. 

Common measures of disability include the Oswestry Disability Index (ODI) and the Short-Form 36 Health Survey (SF-36).  Both of these are quite thorough but again are subject to variability.  The ODI, for example, asks the patient to rate their quality of sleep, sex life and social life.  In my opinion, these are things that are open to wide interpretation (you ask someone about this stuff on a Friday versus a Monday and the answers may vary!).  With so much variability in patients’ responses on VAS and ODI it can be difficult to determine to what extent the patient actually improved after surgery.  Obviously these PROs leave room for improvement.  These days we’re finding that by combining several PRO modalities we can get a more accurate representation of a patient’s progress.

3)  Patients don’t remember how bad they were and thus don’t realize that in fact they’re better.  Recall bias is a well-known entity in medical research.  When asked to recall facts or conditions in the past, research subjects are notoriously inaccurate.  The same applies to spine patients.  A 2017 study out of the Mayo Clinic found significant limitations in how well patients recalled their preoperative VAS scores when asked to recall them a year later. (Aleem et al, 2017)  Also, more than 40% of patients couldn’t remember if it was their back or leg that hurt them more before surgery.  How can a patient tell me if they’re better after my surgery if they don’t remember what was hurting before the surgery. 

Along the same lines, patients may have improper expectations about their surgery and thus may be disappointed in their outcome even when it’s a good outcome.  For example, often patients with lumbar stenosis and spondylosis present with both back and leg pain.  When I consent them for surgery I explain to them that the minimally-invasive laminectomy that I’m recommending will only relieve their leg pain (by fixing the stenosis) and not their back pain.  Some patients don’t hear that though.  After surgery they’ll come back in and tell me that surgery didn’t help them at all.  The exchange goes something like this:

     Me: “Mr. Smith, you’re two weeks out from your laminectomy.  How’s it going?”

     Mr. Smith: “Horrible.  Surgery didn’t help me doc.  You said you were gonna fix me but I’m no better.”

     Me: “Oh no! Tell me where you hurt?”

     Mr. Smith: “My back hurts, Doc.  You said you were going to help my pain.  What happened?”

     Me: “Well how do your legs feel?  Prior to surgery you told me that you couldn’t even walk to the mailbox because your legs hurt so badly.  

     Mr. Smith: “My legs?  Oh they’re great.  Leg pain was gone when I woke up from surgery.  I walked 2 miles this morning. But my back still hurts.”

     Me: (internally) Sigh

I understand why some patients may not fully absorb what I’m telling them.  They’re scared and distracted when the prospect of surgery becomes a reality.   Prospective patients should be mindful of this, though, and make every effort to listen to and process what their surgeon is telling them.   On my end I’m working on ways to ensure that patients hear what I’m telling them so that they can have accurate expectations about their surgery.  This includes detailed handouts discussing surgery as well as audio/video recordings of preoperative conversations that the patient can refer back to when they’re home with their families.  The most well-informed patients will have the most accurate expectations of surgery and thus are most likely to report that they’re better after surgery.

4)  Patients just don’t get better.  Unfortunately some patients, through no fault of their own or the surgeon, just don’t get better.  As much as we like to think we doctors know everything, we don’t.  I think that we just don’t understand every etiology of back pain.  Is it the degenerated disc?  Is it the facet joint?  Has the brain just learned the pain?  There’s just so much we don’t know.  We do our best to make an accurate diagnosis, assess the patient and prescribe an accurate treatment and yet sometimes even that’s not enough for the patient.  This may be the most frustrating thing about what I do.  All I can do is look at myself in the mirror in the morning and swear that I’m just going to do my best for my patients.  Hopefully it’s enough. 

Ok so maybe there wasn’t much technical information in this post.  That’s OK.  Hopefully by hearing my candid thoughts on the matter you’ll be better equipped when talking to your surgeon about the surgery he’s recommending.  Ultimately I love taking care of my patients and just want them to have the best possible outcome after their surgery.  We’re in it together.  If we both do our parts you, the patient, are going to do fabulously after your surgery.   

 

Thanks for reading!

J. Alex Thomas, M.D.

Sources:

Aleem IS, Duncan J, Ahmed AM, Zarrabian M, Eck J, Rhee J, et al.: Do Lumbar Decompression and Fusion Patients Recall Their Preoperative Status? Spine (Phila Pa 1976) 42:128–134, 2017.

True spinal instability is a clear indication for spinal fusion

As we illustrated in our last post there is a wide spectrum of indications for lumbar spinal fusion.   As you move along this spectrum from unstable to more stable pathology the odds of a successful outcome decrease.  At the far end of the spectrum of diagnoses, the end at which there is a lesser chance of a favorable outcome after fusion, is degenerative disc disease (DDD) and spondylosis (without instability) causing back pain.  In my opinion this is softest indication for spinal fusion.  I’m not saying that you should never perform a spinal fusion on a patient with only DDD, the patient just has to be properly vetted and they must understand that a good outcome isn’t guaranteed in these cases.  On the opposite end of the spectrum is acute spinal instability caused by trauma or some other acutely destructive process such as tumor or infection.  This is the clearest indication for a spinal fusion.  NOTE: we’ve already discussed cervical spinal fusion (ACDF) here and here so this discussion will pertain primarily to the lumbar spine.

Classically, spinal stability is defined as the spine’s ability, under normal physiological loads (“normal” obviously varies widely depending on whether you’re a bank clerk or a mixed martial arts fighter), to a) protect the neural elements (i.e. nerve roots and spinal cord), and b) avoid painful deformity.  Sounds complicated right?  It may be easier to think about what happens when the spine becomes unstable: a) it may not be able to maintain proper alignment and thus may become deformed which causes severe pain; and b) it may not be able to properly protect the spinal cord within which could cause paralysis.  So in a nutshell: a stable spine is one that is protecting you against pain and/or paralysis. 

The concept of traumatic spinal fractures is a vast one that I won’t get into too much here.  Generally, though, fractures are classified as stable or unstable (hopefully you’re starting to pick up on a theme here.)  There are many complicated grading schemes that allow spine surgeons to look at a fracture on imaging and determine if it’s unstable or not.  One classic scheme is that of Denis which divides the spine into three columns.  Stable fractures typically only involve one column of the spine. Examples of stable fractures include fractures of the spinous process (a so-called clay shoveler’s fracture, see Figure 2), compression fractures and transverse process fractures.  Stable fractures may be painful from the local trauma of the injury but they do not cause painful deformity nor do they threaten the spinal cord or nerve roots.  Thus these types of fractures may be treated conservatively such as with bracing. 

Mendeley Desktop

Figure 1: Illustration from Denis’ 1983 paper discussing his three spinal columns and their involvement in traumatic injuries.

Clay shoveler fracture Image Radiopaedia org

Figure 2: Fracture of the C6 spinous process (clay shoveler’s fracture).  Source: https://radiopaedia.org/images/3175670

Generally speaking if two or more of Denis’ columns are involved in a fracture it is considered unstable (again let me reiterate that Denis’ model is quite simplistic and analyzing a fracture isn’t always as easy as looking at the spine in only 3 columns.)  When a fracture is determined to be unstable a spinal fusion may be indicated to restore stability.  If an unstable fracture is left to heal without surgery it may heal poorly resulting in a painful deformity. Worse, if a patient with an unstable fracture is allowed to get up out of bed and loads their spine the fracture may shift resulting in injury to the spinal cord and paralysis. 

Trauma isn’t the only cause of acute spinal instability.  Indeed, aggressive tumors or infections can destroy the integrity of the spine thereby causing painful spinal deformity and perhaps paralysis.  These lesions are treated in a similar manner as acute fractures depending on which part of the spinal column has been damaged. The case presentation below describes a case I had a few years ago of an elderly gentleman with severe damage to his spine caused by a staph infection. 

Generally speaking when deciding which type of spinal fusion to perform for acute spinal instability, I’ll go to where the problem is:  if the pathology primarily involves the vertebral body in front of the spine, for example, I’ll do a corpectomy to remove the fractured vertebral body.  Once the body is removed I’ll reconstruct the spine with a spacer inserted where the damaged vertebral body was, and a combination of plating or screws to provide extra stability (we’ll talk about these devices in more detail in future posts.)  The main goal of all of that surgery is to promote new bone growth across the damaged segment of the spine.  It’s this new bone growth that restores spinal stability.  

CASE PRESENTATION:

The patient is a 75yo male with methicillin-resistant staph aureus (MRSA) bacteremia (in his bloodstream) who presents with worsening mid-back pain.  Imaging reveals T11-12 discitis.  (Discitis is an infection of the intervertebral disc space that is probably the most painful condition that I see.  You can usually make the diagnosis by very gently bumping the patient’s bed when you approach the bedside; if the patient screams out in pain it’s probably discitis.  That’s how bad it is.)  The medicine doctors tried a long course of antibiotics but unfortunately his pain didn’t improve.  Repeat imaging revealed that the infection hadn’t been cleared and in fact had caused further destruction of the T11 and T12 vertebral bodies (see Figure 3.) This destruction resulted in spinal instability and kyphosis (a painful deformity in which the spine falls forward.)  

T11 12 discitis

Figure 3: CT scan illustrating T11-12 discitis resulting in severe bony destruction (red arrow) and resultant kyphotic deformity (blue arrow indicates top of spine falling forward). 

When I met this patient he looked like he had given up and wanted to die.  He’d been bedbound from his infection for weeks and now was quite debilitated.  He agreed to undergo surgery and underwent a T11 and T12 corpectomy (via a lateral approach through the chest and behind the lung) followed by reconstruction of the spine with an expandable cage and percutaneous pedicle screws (see Figure 4.)  By one month post-op the patient reported no pain and was walking without assistance.  The last time I saw him about a year after his surgery he was living a normal life at home with his family.  He looked like he’d been given a new chance at life. 

Post op T11 12 corpectomy

Figure 4: Postoperative AP (left) and lateral (right) X-rays with expandable corpectomy spacer at T11-12 (red arrow) and percutaneous pedicle screws from T9-L2 (blue arrows).

I think I’ll spend the next post or two talking about the various forms of spinal implants that we use to achieve a spinal fusion. I had planned to do this later but I think that by presenting it first it will help you better understand the various spinal fusion procedures discussed in later posts. 

 Thanks for reading!

 J. Alex Thomas, M.D.

Sources 

Denis F: The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976) 8:817–31, 1983.

I specialize in “useless” surgery.

On August 3, 2016 the New York Times published an essay called “Why ‘Useless’ Surgery Is Still Popular”.   In the essay the author decries the continued use of medical procedures “despite clinical trials that cast doubt on their effectiveness.”  One of the procedures discussed in the essay, the spinal fusion, is a procedure that I routinely perform on my patients, almost uniformly with great success.  Unfortunately, this essay irresponsibly cites only one review article about spinal fusions and thus unfairly describes the procedure as ineffective and “useless”.  On a professional level I am disappointed in this essay because I think it is misleading to the public and may prevent delivery of a potentially very effective therapy.  Not only may a patient be scared away from getting a spinal fusion after reading the essay, insurers are starting to take notice and have pounced on the opportunity to not have to pay for their patients to have fusions, deeming them “medically unnecessary”.   On a deeper, more personal level, articles like this really burn me up (and I really have to bite my tongue to remain professional there.)  I work tirelessly to provide the best possible care for my patients and spinal fusions comprise a large part of my practice.  You can imagine how I feel when articles like this in the mass media attempt to discredit what I do to help so many people.

Like any surgical procedure, the key to a desirable outcome is to only perform spinal fusions on patients with the proper indications for the procedure.  The “useless” author cites a review article by Mirza et al in 2007 that compiled data from 4 randomized trials of lumbar spinal fusion for discogenic back pain.  These trials found that spinal fusions were no better than physical and cognitive therapy for treating chronic low back pain.  The issue here, as it usually is whenever a surgery fails, is the poor indication for surgery.  First of all, any reputable spine surgeon knows that you should never offer surgery to a patient with only back pain.  There must be a corresponding structural cause of the patient’s pain that is amenable to surgery and the patient’s physical exam findings must correlate with these structural problems.  A degenerating disc causing so-called discogenic pain is NOT a structural cause of back pain!!  We’re not even certain that a degenerating intervertebral disc (IVD) can cause pain.  The thought is that by removing the degenerated and thus painful disc and fusing the adjacent vertebral bodies you will relieve the patient’s pain.  Unfortunately, so called “black disc surgery” (because the discs get darker as they degenerate) usually doesn’t work.  In my opinion this is the softest indication for spinal fusion and in fact most insurers won’t even approve the procedure for this indication. The vast majority of patients who present to my clinic with chronic discogenic back pain are sent right back out for pain management, physical therapy or other forms of conservative management.  

Spinal fusions are clearly effective in correcting structural problems of the spine such as spondylolisthesis and degenerative scoliosis.  That’s not just my anecdotal belief; multiple clinical studies have proven so.  For example, in the landmark randomized, controlled SPORT study published in the New England Journal of Medicine in 2007, Weinstein et al looked at spinal fusion versus nonsurgical treatments (i.e. physical therapy, epidural steroid injections, etc.) for the treatement of spondylolisthesis (a painful condition where one vertebral body slips over the one below it.)  The study demonstrated clear superiority of spinal fusion over nonsurgical treatments (see figure 1.)  The benefits of spinal fusion have been found to persist out to at least 8 years in subsequent analyses.  Patients who underwent nonsurgical treatment also got better, just not as rapidly or to the same extent as patients who underwent spinal fusion.  Finally, it’s important to note that the benefits of spinal fusion in the SPORT study were seen for fusion techniques that in my opinion are a bit archaic in the age of advanced minimally-invasive techniques.   Of course, the “useless” author didn’t discuss seminal studies such as SPORT in her essay.   

W CT CAT SCAN LUMBAR SPINE WO CONTRAST Win

Figure 1: A successful minimally-invasive spinal fusion done at L4/5 for spondylolisthesis. 

Over the next several posts we’ll discuss the indications for spinal fusion as well as the various techniques used to achieve a spinal fusion.  Hopefully you’ll learn what I already know: that spinal fusions, when done for proper indications, can dramatically improve a patient’s function and quality of life.   

Thanks for reading!

J. Alex Thomas, M.D.

Sources

Weinstein, J. N., Lurie, J. D., Tosteson, T. D., Hanscom, B., Tosteson, A. N. a, Blood, E. a, … Hu, S. S. (2007). Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. The SPORT authors. The New England Journal of Medicine, 356(22), 2257–70.