Candidates for spinal fusion include those who have persistent pain that has not alleviated with conservative treatment, and where spinal instability or weakness appears to be the cause of the pain. Some patients who have undergone other back surgeries such as discectomy, foraminotomy, or laminectomy, may also be candidates for spinal fusion as these procedures can contribute to a weak or unstable spine. Infection or tumors in the spine may also affect its curvature and motion, as can conditions such as scoliosis, spondylolisthesis, spinal stenosis, trauma, and fracture of the vertebrae.
Minimally invasive spinal fusion can be performed in some cases and should be discussed with the physician when making treatment decisions. This technique can reduce the degree of trauma on surrounding tissues, shorten recovery times, reduce post-surgical pain, and is associated with lower rates of infection, blood loss, and complication. Incision sites can be in the back, abdomen, side, or a combination, to all the surgeon access to the spine. Spinal fusion surgery through the abdomen is associated with a higher potential for nerve trauma making other approaches preferable.
Spinal fusion may be conducted after another back surgery, such as laminectomy or discectomy in order to maintain the strength and stability of the spine which can be compromised by such procedures. It is not always necessary, or beneficial, if only single vertebral levels are operated on. Sciubba (2008) conducted a study of ten years of clinical cases of laminectomy without fusion in patients who required the procedure for a dural tumor resection. Among the observations were a propensity for those having a three (or more) level laminectomy to require fusion surgery at a later date; approximately 33% of patients in this group required additional surgery after two years or so, compared to approximately 5% of those undergoing laminectomy on two levels or less.
In the majority of cases laminotomy and laminoplasty do not indicate a need for spinal fusion as part of the same surgery or in the short-term. The use of an autograft or allograft will also be discussed prior to surgery and the surgeon will explain options for instrumentation to attach the graft and aid fusion.
Multi-level back surgery fusion animation (Medtronic)
Quitting Smoking Prior to Surgery
Patients who smoke will be asked to quit before surgery. This is extremely important as spinal fusion has a significantly lower success rate for smokers due to the inhibition of bone growth by chemicals such as nicotine. One study found that 40% of smokers failed to achieve fusion after surgery, compared to just 8% of non-smokers (Brown, 1986). Smoking also affects circulation and is associated with an increased risk of complication with any type of surgery. It is also important not to smoke during the recovery period. Those who take medications, such as NSAIDs, analgesics, or herbal or nutritional supplements may need to stop these for a time before surgery. It is important the the physician knows of all medications a patient is taking, whether prescribed or over-the-counter, as some can increase the risk of excessive blood loss during surgery. A schedule for the cessation and resumption of medications should be set with the doctor prior to surgery.
It is also advisable to not drink alcohol for a few days prior to surgery as this can also cause complications surrounding the ability of blood to clot. Any signs of infection may delay the spinal fusion surgery and a thorough physical will be conducted to rule out infection before the operation begins. As spinal fusion is conducted under general anaesthetic, patients should not eat or drink anything from midnight the night before surgery. If drugs have to be taken then small sips of water are allowed. Once a patient arrives at the hospital they will be given a sedative and then a general anaesthetic and rolled onto their front to allow the surgeon access to the spine (in most spinal fusion procedures a posterior approach is preferred).