Going off our last post, lets start by looking at some surgical options for spinal conditions. And lets start with the most invasive and controversial: the fusion. Granted, you can fuse any two vertebrae together, but we'll focus on the lumbar region (the last five vertebrae of the spinal column), as this is the most common area we see in the clinic.
Two of the main conditions that would warrant a lumbar fusion are spinal stenosis (mentioned in a previous post) and spondylolisthesis (check out the second link below for great visual aids). These two conditions in their "severe" state can have significant irreversible and long-term effects. While we have seen people get better with physical therapy in that situation, sometimes surgery is inevitable. The good news is that even if it is decided that a fusion is necessary, the current techniques are significantly less invasive (smaller scar, less cutting) than even ten years ago.
Generally the most commonly fused vertebra pairs are L4 - L5 (the last two lumbar vertebrae) and L5 - S1 (the last lumbar vertebra fused to the sacrum). This is where spondylolisthesis is almost always found, and where the majority of lumbar vertebral instability occurs. If the condition is from a single disc or an isolated area, fusion may be unnecessary as a microdiscectomy (small portion of the involved disc cut out) may be all that is required. While much less invasive, a discectomy will not help correct instability while a fusion is meant to do just that. This is generally where the controversy arises - to do a fusion or to opt for a simpler and less invasive (and cheaper) surgery and see if you can get by with less. Much has been made recently about health care costs and avoiding more complicated (and more expensive) surgeries if less will be as effective.
There certainly are risks with every surgery, but even more so when the spine is involved as nerve damage can be permanent. There are many studies showing that people who smoke have a significantly high chance of failure post-surgical, meaning the fusion doesn't "take" or heal properly and that another surgery is required to fix it. Because of this, many surgeons will refuse to perform surgery on a patient who smokes. There is also the chance that another future surgery will need to be performed at the next level up or down from the surgical site. Some people will note immediate relief of pain post surgery, and some will note little to no relief of pain. Many surgeons will only consider fusion if all conservative measures (injections, therapy, etc) have failed. Unfortunately there are no guarantees, and only you and your doctor can make the serious decision of how to proceed.
Rehab following fusion will depend on the method and surgeon. Some surgeons will allow for more aggressive rehab. Many surgeons will recommend a back brace for a period of time. Rehab will focus on general strengthening and conditioning as most patients will be very deconditioned from being so limited prior to surgery. Aquatics can be a great way to lightly strengthen and also take much stress off the spine from the buoyancy of the water. Abdominal/core strength will be a key to rehab also as, generally speaking, the more your abs work, the less your back has to. There are usually bumps along the way, but the road to recovery can be made. Good luck!
For a brief overview of the what's and how's: http://www.spineuniverse.com/treatments/surgery/lumbar/understanding-lumbar-fusion-surgery
Check this site out for some awesome visual aids and great info: http://www.spinalneurosurgery.com/Lumbar%20Fusion.htm
Some facts and myths from a neurosurgeon: http://neurodallas.com/Spine-Facts-Myths.html
A look at fusions and disc replacement: http://www.centerforspinecare.com/orthopedicsarticle/myths.html
For a very thorough article on all options: http://nursinglink.monster.com/training/articles/266-lumbar-intervertebral-disc-herniation