If you are reading this page as a patient, it is imperative that you have first read the pages The Spine - Basic Anatomy and Mechanics, Causes of Back and Neck Pain, Radiculopathy, and Minimally Invasive Lumbar Spine Surgery. If you haven't read them, a lot of what follows will not make sense.
The goal of reconstructive spine surgery is to alleviate the symptoms of back and leg pain. Remembering of course that leg pain can have both radicular components and referred pain components. Lumbar spine reconstruction can get rid of severe, disabling, pathological pain both in the back and legs. It rarely, if ever, gets rid of simple aches and pains that would be considered normal for the average age and sex-matched individual.
If you are a patient reading this page, something has gone drastically wrong in your spine for all the reasons mentioned in the 'back pain' page and the 'radiculopathy' page. It is important to realise that lumbar spine reconstruction can provide an improvement as long as the proper care is taken. The end result of successful reconstructive spine surgery needs to be protected as much as your native spine needs to be. Basically, you cannot expect to have surgery on your spine and then get back to doing whatever was responsible for your deterioration in the first place. Spine surgery, no matter how successful, often takes someone to either the next stage of their life, or at least sideways down a different lifestyle.
Modern spine surgery focuses on reconstructing the spine. In other words, restoring the anatomy, as close as possible, to the non-degenerate state. This means replacing the lordosis, especially at L4/5 and L5/S1, and restoring disc height (and therefore stability) to each motion segment responsible for your symptoms, without causing too much in the way of collateral damage in the process.
Types of Spine Surgery
Reconstructive spine surgery is different from decompressive spine surgery (where the roof is removed from the back of the spine to free up nerves and the spinal cord) and different from "fusion in situ" surgery where, following decompression, the spine is fused in whatever deformed position it was in prior to surgery. There are circumstances were purely decompressive spine surgery is indicated, but I perform this very rarely in my practice. The philosophy behind fusion in situ surgery really stems from the days when the instruments and technology to reconstruct the spine were not available. In some instances, fusion in situ works by providing stability to a deformed segment of the spine but often leads to further surgery being required at a later date because of the consequences of being fused in an unbalanced position.
Reconstructive spine surgery is different from decompressive spine surgery (where the roof is removed from the back of the spine to free up nerves and the spinal cord) and different from "fusion in situ" surgery where, following decompression, the spine is fused in whatever deformed position it was in prior to surgery. There are circumstances were purely decompressive spine surgery is indicated, but I perform this very rarely in my practice.
The philosophy behind fusion in situ surgery really stems from the days when the instruments and technology to reconstruct the spine were not available to the extent they are today. In some instances, fusion in situ works by providing stability to a deformed segment of the spine. This often leads to further surgery being required at a later date because of the consequences of being fused in an unbalanced position.
Lumbar spine reconstruction, as mentioned previously, aims to restore height and lordosis to each degenerate segment. There are many ways to complete a lumbar spine reconstruction and every spine surgeon you see will tell you his / her way is the best way. The truth is, you are in good hands if you can find a surgeon that:
- Understands the importance of restoring anatomy.
- Has a good track record.
- Can openly talk to you about his / her failures with as much honesty as their successes.
- Appears to be omnicompetent - in other words, can decide on the reconstruction method based on what is best for your individual situation rather than simply relying on one method for every case.
Figure 1 (below) shows a patient whose x-ray had 3 level degenerative disc disease at L3/4, L4/5 and L5/S1. The lower two levels have had height and lordosis restored and stabilised with a cage / plate construct packed with bone substitute, the L3/4 level has been reconstructed with a moving disc replacement, which is a prosthesis that moves physiologically with the remaining spine.
In this case 12 degrees of flexion / extension was produced at L3/4. You can see that the neuroforamen at each operated level has been opened up (and now looks equal in size to the unoperated levels above) by expanding the disc space. The back pain decreased by about 80% as a result of the pain generator (the degenerate disc) being removed, and the facet joints located in their normal position. The base of the neck was repositioned over the sacrum restoring overall spinal balance. This reconstructive spine surgery procedure usually takes about 2-3 hours to do and requires 5-6 days in hospital. Return to work is possible on light duties about 4-5 weeks later and about 6 months of physiotherapy to get the full benefit.
It is impossible to predict exactly what result in terms of symptom reduction will be achieved by lumbar spine reconstruction. The main reason for this is that in subtle ways every single person's spine, and their degenerative pattern, is different. The results depend on:
- How many levels need to be reconstructed and how badly degenerate they are.
- Whether or not the nerves are radiculopathic (as opposed to radiculitic).
- The presence of any medical / psychiatric problems.
- The patient's general physiology.
- The patient's expectations and personality.
- The involvement of legal proceedings and WorkCover (or any third-party insurer) claims.
Many patients come to our clinic now having already had some form of non-reconstructive spine surgery in the past, which can make results unpredictable as a result of scarring and adhesions. As a general rule, patients who have had reconstructive spine surgery fall into one of three groups post-operatively.
About 75%-80%% of patients report at the 6-month follow-up that they are extremely satisfied with their symptom reduction. Usually this means they have experienced between 70% - 80% relief of their pain and a similar improvement in function. Some of these patients report this degree of pain relief quite quickly, some take the full 6 months to get there. It is not unusual for a younger patient with single, or two level disc disease, with the appropriate level of motivation and rehabilitation to experience 100% relief of their symptoms. In a paradoxical way, these are the patients who worry us in terms of their ability to wind up in trouble later on because of a tendency to return to the same level of activity that led to their deterioration in the first place.
About 15%-20% of patients report at the 6-month follow-up that they still have some back and leg pain, but it is considerably better than before the lumbar spine reconstruction. Usually they rate their symptom reduction around the 60-65% mark. Usually these are patients who have had prior spine surgery, usually of a purely decompressive (as opposed to reconstructive) nature, patients who have severe nerve damage (radiculopathy) and whose nerves are still regenerating / recovering.
Some patients who have been treated with high doses of narcotics for decades because of severe pain become narcotic dependent and even successful reconstructive spine surgery cannot get them free of the dependency, and so the perception is that they still have pain. Patients under the jurisdiction of WorkCover and who are involved in legal proceedings have a higher chance of ending up in this group and we have no intelligent ideas as to why.
Overall about 5% of patients will say that reconstructive surgery has not changed their symptoms. The reasons for this can sometimes be worked out as other things come to light in the months following surgery, but not always. Patients who fall into this group include those experiencing:
- Significant osteoporosis (soft bone).
- Medical complications.
- Abnormal psychometric personalities.
- Legal issues.
- Poor motivation to improve.
- Complications from surgery.
It is very rare to find a patient in this group because of something going wrong during surgery. If anything is not quite right during the lumbar spine reconstruction it is usually picked up right away and corrected. Sometimes, however, a patient can be completely normal, have a perfect diagnosis, cross all the boxes to make a good candidate for surgery, have technically excellent surgery performed and still not get a reduction in their symptoms. This is extremely rare and usually no explanation is available. At the end of the day, our decisions to operate are based on subjective tests, experience, a clinical history and examination and a patient's personal decision that the risks are worth undertaking based on the severity of their symptoms. We use evidence-based medicine to guide this process and all the data from this evidence clearly talks about failure rates.
All surgery, from having complex brain surgery for example to banding of haemorrhoids, has a risk profile. The risks of reconstructive spine surgery can be divided into 2 categories.
These are complications which, if they occur, mean that the surgery has failed, and you may even be worse off than before surgery. These complications are extremely rare and include things like:
- Deep infections around the spine.
- Nerve damage.
- Damage to any of the structures that need to be moved out of the way to get access to the spine like the bowel, ureters and major blood vessels.
- Aspirating food contents into the lungs during anaesthesia.
- Formation of blood clots in the weeks following surgery (DVT) or their lethal counterpart - pulmonary embolism.
- Significant medical complications as a result of unstable co-existing pathologies, which may or may not be evident at the time of booking surgery.
These complications are devastating if they happen but, fortunately, extremely rare. In this day and age, the biggest factor leading to failure of reconstructive spine surgery is osteoporosis (soft bone). We have found through bitter experience that pre-operatively testing for soft bone is unreliable. If encountered and recognised during surgery some measures can be taken to mitigate against the reconstruction collapsing.
These include things like:
- Superficial wound issues.
- Temporary urinary or chest infections.
- Ileus (which is where the bowel goes to sleep for a few days as a result of the anaesthetic and being manipulated during surgery).
- 'Odd sensations' from nerves waking up and regenerating.
- Allergic-type reactions to bone graft substitutes.
- Some increased pain for a while as your spine gets used to its new position and alignment.
These complications may linger around for a few weeks or even months but usually have no long-term adverse effect on the outcome provided advice and treatment is followed.
Prior to any surgery, you will be provided with a comprehensive leaflet which details all the risks relevant to your lumbar spine reconstruction operation and any specific risks relevant to you.
How it is performed
Tests such as discography, nerve conduction studies, MRI, dynamic x-rays etc. indicate what levels need to be reconstructed. It is then decided how each level is to be approached. Various types of degeneration are reconstructed with different types of technology.
Sometimes the approach taken to a level in the spine depends on what technology is to be deployed there. Sometimes a patient's anatomy dictates what approach is best used. Other times it is simply what approach I feel most comfortable using, on the basis that the easiest, and least stressful operation usually has the best outcome.
Whether PLIF (posterior), ALIF (anterior), XLIF (extreme lateral) or AXIALIF (trans-sacral) approaches are used, if you have multiple motion segments involved it is likely you will have a combination of approaches. Often these will be performed in one operation but many times it is better, and safer to perform the lumbar spine reconstruction in two stages spaced a few days apart. Another reason for performing the operation in two stages is to assess the clinical efficacy of stage 1 prior to making clinical decisions about other parts of the spine, requiring an opportunity to talk to or stand / walk the patient in between stages.
Every patient more-or-less gets an individualised lumber spine reconstruction. Just because there is degeneration in a motion segment doesn't mean that it has to be operated on or reconstructed. The goal in every patient is to perform enough surgery to get someone out of trouble, without exposing them to unnecessary surgery and, therefore, unnecessary risks.
Over the age of 60
Everyone over the age of 60 will have degeneration to some degree in all their discs but usually only 2 or 3 need reconstructing. I try very hard to place some motion preservation (i.e. disc arthroplasty) in my reconstructions. There is good evidence in the literature from well-respected spinal surgeons that a disc arthroplasty, if it performs and moves physiologically (over 5 degrees of flexion but not over 15 degrees), prevents adjacent segments in the spine from becoming symptomatic (Huang et al 2007).
There is an old adage that there is little value in having your spine operated on as it hastens the deterioration of discs higher up in the spine. This is a direct result of old-fashioned operations that expose the motion segments higher up with large, tissue destroying approaches to the spine, and by operations that fail to restore height and lordosis. No-one really knows if performing minimally invasive fusions increases the risk of degeneration spreading to adjacent segments. Depending on what you read in the literature the rate of adjacent segment degeneration with anterior fusions varies from 8% to 40% between 5 and 15 years following surgery. That literature however is not clear on what diagnostic tests like discography, if any, were performed to assess the other discs prior to surgery and many of those anterior procedures were coupled with traditional, open, posterior procedures, which we know damage the motion segments above.
Many spine surgeons, including myself, believe that the risk profile of other discs in the spine is not changed by operating on the very degenerate segments when minimally invasive techniques are used. Those discs are already over-worked considerably by the spinal imbalance and instability caused by the degenerate segments, and their fate was probably sealed long before reconstructive spine surgery.