Failed back syndrome (FBS), also called “failed back surgery syndrome” (FBSS), refers to chronic back and/or leg pain that occurs after back (spinal) surgery. It is characterized as a chronic pain syndrome. Multiple factors can contribute to the onset or development of FBS. Contributing factors include but are not limited to residual or recurrent disc herniation, persistent post-operative pressure on a spinal nerve, altered joint mobility, joint hypermobility with instability, scar tissue, depression, anxiety, sleeplessness and spinal muscular deconditioning. An individual may be predisposed to the development of FBS due to systemic disorders such as diabetes, autoimmune disease and peripheral blood vessel disease. Smoking is a risk for poor recovery.
Common symptoms associated with FBS include diffuse, dull and aching pain involving the back and/or legs. Abnormal sensibility may include sharp, pricking, and stabbing pain in the extremities. For patients with continued pain after surgery which is not due to the above complications or conditions, interventional pain physicians speak of the need to identify the “pain generator” i.e. the anatomical structure responsible for the patient’s pain. To be effective, the surgeon must operate on the correct anatomic structure; however it is often not possible to determine the source of the pain. The reason for this is that many patients with chronic pain often have disc bulges at multiple spinal levels and the physical examination and imaging studies are unable to pinpoint the source of pain In addition, spinal fusion itself, particularly if more than one spinal level is operated on, may result in “adjacent segment degeneration”. This is thought to occur because the fused segments may result in increased torsional and stress forces being transmitted to the intervertebral discs located above and below the fused vertebrae. Removal of a disc at one level can lead to disc herniation at the same level or a different level at a later time. Even the most complete surgical excision of the disc still leaves 30-40% of the disc, which cannot be safely removed. This retained disc can re-herniate sometime after surgery.
In a groundbreaking Canadian study, Waddell reported on the value of repeat surgery and the return to work in worker’s compensation cases. They concluded that workers who undergo spinal surgery take longer to return to their jobs. Once two spinal surgeries are performed, few if any ever return to gainful employment of any kind. After two spinal surgeries, most people in the worker’s comp system will not be made better by more surgery. Most will be worse after a third surgery. Recent studies have shown that cigarette smokers will routinely fail all spinal surgery, if the goal of that surgery is the decrease of pain and impairment. Many surgeons consider smoking to be an absolute contraindication to spinal surgery. Nicotine appears to interfere with bone metabolism through induced calcitonin resistance and decreased osteoblastic function. It may also restrict small blood vessel diameter leading to increased scar formation.
There are certain cases where spinal surgery is absolutely necessary, however every possible conservative option should be exhausted prior to spinal surgery in most cases.