Etiology of long-term failures of lumbar spine surgery

Patients who do not improve after lumbar surgery may be given the nonspecific label of "failed back surgery syndrome (FBSS)." Since 1981, there has not been a quantitative assessment of the etiologies of FBSS despite major improvements in surgical techniques and diagnostic testing.

To define the causes of FBSS seen in a referral-based spine center.

Retrospective review of 181 consecutive charts of patients seen at a single spine center because of continued pain after lumbar surgery performed elsewhere. Evaluation was individualized based on history and physical examination and included x-rays, CT scans, MRI, selective nerve root injections, discography, and psychiatric evaluation.

There were 101 men and 80 women; mean age was 47 years. There were 118 patients with one prior surgery, 52 with two, 6 with three, and 5 with four. Mean interval from the last prior surgery to the first clinic visit was 33 months.

A predominant diagnosis could be established in 170 of 181 (94%) patients, and included foraminal stenosis (29%), painful disc(s) (17%), pseudarthrosis (14%), neuropathic pain (9%), instability (5%), and psychological problems (3%).

We were able to establish a predominant diagnosis in 94% of our patients. Foraminal stenosis remains the leading cause of FBSS, but painful discs are also common. Recurrent disc herniation is seen less often than in the past, and there is increased recognition of neuropathic pain. Knowledge of the potential causes of FBSS leads to a more efficient and cost-effective evaluation of these patients.