In the general US population in 1992, $49.2 billion was spent on back-pain-related disability, accounting for the largest single proportion (34%) of all occupation-related injury costs in that year. Put in perspective, this amount falls between the amount spent treating and compensating AIDS ($30.0 billion), and Alzheimer's ($67.3 billion), and is about a third of the total costs of circulatory and heart
disease ($164.3 billion). Eighty percent of these costs are consumed by the 10% of the back pain cases where disability persists longer than six weeks. Finding treatment programs that prevent work-disability from developing into a chronic, long-term condition could save considerable health care resources. Low back pain is most common between the ages of 30 to 45 years and the incidence is nearly equal among males and females. It is the single most common cause for disability in persons under age 45.
Most individuals suffering with low back pain recover spontaneously in 4 to 6 weeks, however many experience recurrent episodes later in life. For those patients who do not recover spontaneously, treatment begins conservatively, with only a small percentage ever requiring surgical intervention for severe recalcitrant low back pain. Yet despite this, there are more than 200,000 lumbar fusion surgeries performed in the U.S. each year.
Low back pain is ubiquitous in our society, affecting nearly 80% of the adult population at some time during their life. It represents the single most common cause for disability in persons under age 45.
Lumbar spinal fusion is an accepted treatment for painful lumbar degenerative disc disease that has failed conservative treatment. Over the years, a variety of fusion techniques for the lumbar spine have evolved, from bone graft alone, to the addition of spinal instrumentation as an adjunct to improve fusion rate. More recently, lumbar interbody fusion techniques have been developed to provide solid fixation of spinal segments while at the same time, maintaining load-bearing capacity and proper disc height. Each technique for lumbar fusion has its advantages and disadvantages, but in general, the type of surgery a physician chooses to perform is typically based on the nature of the pathology.
The main disadvantage of the posterior procedures is the injury to the stabilizing posterior spinal muscles and their nerve supply, which may be a source for continued loss of function and pain. The long incisions, extending well above and below the spinal