I see a number of patients in the office with a whole collection of various neck and low back problems. Sometimes they have relatively few medical problems and are quite healthy and active, but in many cases patients do have other medical issues on top of their spine problems. The research that we have done as a community of spine surgeons over the past several years has been very helpful into understanding the impact of those medical problems on the success and safety of spine surgery. I thought I would spend a little time today and explain some of those principles to you and why the spine division of Orthopedics Rhode Island cares so very much about these principles.
Complications during and after spine surgery
There is a whole host of complications that can occur during or following any spine surgery that we perform. As surgeons, we will very commonly ask ourselves if there was anything that we could have done differently to prevent a complication in the days, weeks and months following one of these events after surgery.
We worry about failure to achieve a successful spine fusion, or pseudoarthrosis, as well as instrumentation failure or breakage after surgery. In many cases we are performing fusion surgeries to stabilize segments of the spine in addition to decompressing nerves. The point of stabilization and fusion is to prevent recurrent nerve compression. In order to do this, we will place instrumentation into and in between bones of the spine along with bone graft so that over the several months to a year following the surgery the bones eventually unite to become one. I think the most important thing to realize with a fusion surgery is that it is your own body's biology that actually makes the fusion work down the line. The surgical techniques that are utilized during surgery are obviously very important to ensuring that a fusion can be successful, but I think that a patient's biology is just as, if not, more important. The analogy that I use quite often is that we as spine surgeons are essentially laying down a foundation in the form of screws, rods, cages and/or plates along with bone graft when we perform a fusion surgery; but it is your body that ultimately builds the house on top of that foundation. If a fusion does not successfully form, we sometimes have to perform one if not more additional surgeries to achieve a successful fusion. This may mean that prior hardware or instrumentation needs to be removed or replaced.
We worry about infection and wound breakdown after surgery. Many surgical site infections are actually caused by the bacteria that live on our skin to begin with and the rate of infection in all spine surgery cases is roughly 1 in 200 (or 0.5%). We know that surgical site infections are more common during fusion surgeries in which instrumentation (screws, rods, cages and sometimes plates) is being placed in the spine. We know that revision surgery (or surgery being performed after already having had a prior spine surgery in that area) is associated with higher rates of surgical site infections; this is likely due to the fact that scar tissue does not heal together as well as normal tissue that has not undergone any prior surgery. We know that undergoing a steroid injection in the area of a surgery within a 6-week period leading up to that surgery also raises the chance for a surgical site infection. To treat a surgical site infection, we tend to have to perform one if not more additional surgeries to clean the infection out and help ensure that your surgical wound can heal cleanly. This will also require a course of IV antibiotics followed by oral antibiotics; the length of antibiotic treatment can vary from several weeks to a few months, but there are cases where patients need to take antibiotics for the rest of their lives. So with regard to these specific points, we have surgeons do a number of things to cut down the risk for surgical site infections. We test patients for a specific type of resistant bacteria called MRSA prior to surgery and then help them go through a decolonization process in the week prior to surgery if they test positive. We always give patients a preoperative antibiotic prior to making our surgical incision and perform the surgeries in a sterile environment with our standard hospital protocols. We, in many cases, place an antibiotic powder in the surgical wound prior to closure. And we also will time our surgeries outside of the 6-week window following any type of local steroid injection in the surgical area.
We worry about spinal fluid leaks during surgery. The main reason that we perform the majority of spine surgeries is to decompress nerves in either the neck or the back to get either the arms or legs to feel better. There is a huge misconception that spine surgery is utilized to “fix” isolated neck or back pain - but I am going to leave that topic for another blog post. The nerves themselves live in a bag of spinal fluid; that bag is called the dura and is sort of similar to Saran wrap. So within the bag of fluid, the nerves want to be able to float nice and freely as they travel from the brain down through the neck and the mid back and into the low back and eventually into the legs without any areas of compression. When we are decompressing the nerves in either the neck or back to get those arms or legs to feel better we actually have to remove bone and soft tissue that has built up over the years and is now pressing on that bag of fluid and subsequently on those nerves. During lumbar spine surgery there is about a 7 to 10% chance of accidentally creating a small hole in that bag of fluid that then allows the fluid to leak out; and that risk is even higher in cases of revision surgery (or surgery being performed after already having had a prior spine surgery in that area) due to scar tissue formation. If a spinal fluid leak occurs during surgery, we repair that leak by sewing it back together and typically sealing it over with some type of surgical sealant material. We do not want that fluid to continue leaking out; so, following surgery, we sometimes lay patients flat in bed and then gradually check them for spinal fluid headaches the following morning as we raise their head of the bed while in the hospital. It is important to know that getting a spinal fluid leak during surgery does not impact your chance of neurologic recovery and improvement in your nerve symptoms but it does change your length of stay in the immediate postoperative experience while in the hospital.
This is just a list of some of the many complications that can occur during and after spine surgery. We of course worry about blood clots and strokes, and heart attacks all of which can be potentially fatal. Spine surgery is a very serious undertaking and because of that we as surgeons do not take it lightly. We want to get you through these surgeries as safely as we can - period. And in the next section we will get into why it makes sense to hold off on a surgery until certain medical problems have been addressed and optimized. I want to stress that we are not trying to take surgery off the table forever; but in order to protect you from complications, surgery may have to be off the table until the medical problems have been addressed and optimized.
The impact of medical problems on complications of spine surgery
So, the first medical problem that I think makes sense to discuss is diabetes along with obesity, as the two can tend to go hand in hand. We know that diabetic patients with a hemoglobin A1c above 8.0 are at a much higher risk for surgical site infections. We know that patients with a body mass index (or BMI) over 40 are at a much higher risk of an intra-operative spinal fluid leak, a post-operative surgical site infection, and incurring a number of the medical complications after surgery (blood clots, heart attacks, death). For this reason, we have to work in a team approach with your primary doctor, endocrinologists, nutritionists and sometimes gastric bypass surgeons in order to create a safe medical scenario for surgery. This does mean that your spine surgery would have to be delayed until either your diabetes or weight or both have been managed successfully. We are not trying to say that we aren’t willing to take care of you; we are trying to say that we do need to take care of you safely, the way I would ask that any of my family members be treated.
The next medical problems that we should discuss is nicotine use. We know that patients with nicotine in their system are at a much higher chance for developing a pseudoarthrosis (or failed fusion) which would then make it more likely for them to require a subsequent surgery to then achieve a successful fusion. We know that patients with nicotine in their system are at a much higher chance for developing a surgical site infections which would then require subsequent surgery and either temporary or lifelong courses of antibiotics to treat that infection. We also know that patients with nicotine in their system are much less likely to recover clinically even if they make it through surgery without developing infection or pseudoarthrosis; their nerves simply do not recover nearly as well as a patient without nicotine in their system. We also know the patients with nicotine in their system are less able to participate in the necessary functional rehab after surgery which certainly impacts their success altogether following surgery. For this reason, we have to work again in a team approach with your primary care physician and some of the nicotine cessation programs in the area to get patients off of nicotine prior to surgery. We do require that patients be nicotine free for at least 4-weeks prior to surgery and perform nicotine test at our presurgical visits; we also stress staying off of nicotine for a year after surgery in order to optimize nerve recovery, fusion success and decrease infection risk. This does mean that your spine surgery would have to be delayed until you have been nicotine-free for 4-weeks. We are not trying to say that we aren’t willing to take care of you; we are trying to say that we do need to take care of you safely, the way I would ask that any of my family members be treated
The last medical problem I think we should address is osteoporosis. In many cases we are placing screws, rods, cages and possibly plates in the spine to correct curves, stabilize and fuse segments of the spine. The difficulty with placing this type of instrumentation into the spine in the setting of osteoporosis is hardware failure. If the patient has very thin or poor quality bone, the screws and rods can pull out of the spine and the cages cannot collapse or fracture into the bones of the spine themselves. In the scenarios, patient can be left in a worse set of circumstances following surgery that they were dealing with prior to surgery. In cases of potential osteoporosis as we are evaluating patients with spine complaints, we will obtain both lab work as well as bone density scans to assess their bone quality. If the patient is dealing with osteoporosis, we have our own team of specialists within our Bone Health Clinic that can help patients start managing their osteoporosis with medication. We typically recommend optimizing an osteoporotic patient’s bone density over the course of a year prior to surgery.
Spine surgery isn’t just about your spine
I hope that the biggest take away from this blog post is that spine surgery is rarely just about your spine. We, as a team of specialists, really do have to help you balance your other medical problems to get you through a spine surgery safely and successfully. I hope that this was a helpful overview of some of the things that we are trying to balance and weigh when we are treating patients with spine problems.