When is spinal fusion warranted in degenerative lumbar spinal stenosis?

This study, conducted by a group of neurosurgeons who devote a large portion of their professional time to the treatment of degenerative lumbar spine lesions, was prompted by the dramatic increase in the number of lumbar spinal fusion procedures performed over the last few years in a broad spectrum of disorders ranging from chronic incapacitating low back pain to lumbar spinal stenosis. In the authors' experience, lumbar spinal fusion is rarely warranted and often of dubious efficacy. To investigate this contradiction, the authors reviewed the medical literature on lumbar spinal fusion for the treatment of degenerative spinal stenosis. They have defined lumbar instability as objectively as possible, reviewed clinical and roentgenographic features, described spinal fusion techniques with the drawbacks of each, and evaluated outcomes of surgery for degenerative lumbar spinal stenosis with or without fusion. Findings demonstrate that spinal fusion is a technique of unproven benefit that should be used only in carefully selected patients until results of reliable, prospective, comparative clinical trials become available. In the authors' opinion lumbar spinal fusion should be used as the first-line treatment only in young patients with clinical manifestations directly related to lumbar instability as defined in this study, when decompression requires removal of both facet joints and of the disk (which is rarely the case) or when simple decompression is followed by a recurrence of symptoms ascribable to worsening vertebral slippage.