Medical Device Daily Washington Editor

Orthopedic surgeons have digested a number of mixed signals on whether to operate on a patient who presents with lumbar disc herniation, but a fairly large trial designed to offer decisive evidence ended up reaffirming the emerging mindset that, with a few exceptions, the patient should take a crack at non-surgical therapy before opting for surgery.

The study, dubbed the Spine Patient Outcomes Research Trial (SPORT), appears in the Nov. 22 edition of the Journal of the American Medical Association (JAMA), and compared surgery vs. therapy for 501 patients between 2000 and 2004 who were randomly assigned to the two study arms. Another 743 patients decided their treatment in advance, forming an observational cohort (intent-to-treat).

Among the inclusion criteria were pain below the knee (for those with lower lumbar herniation), pain above the knee (upper lumbar), and evidence of root-nerve irritation as indicated by raised-leg tension. Those who had undergone previous spinal surgery were excluded, as were those with cauda equina syndrome, a compression of nerves that control, among other things, bladder and bowel function.

The authors stated that "both operated and non-operated patients with intervertebral disc herniation improved substantially over a two-year period." Patients in the intent-to-treat group "showed no statistically significant treatment outcomes," but a secondary measure, severity of symptoms of sciatica, "did show statistically significant advantages for surgery." However, the authors argue that this outcome should be considered in the light of a "pattern of non-adherence" to therapy, which apparently was characteristic of those who underwent surgery and those who did not.

"The major limitation of SPORT," the authors state, "is the degree of non-adherence with randomized treatment," a reference to the substantial numbers of patients who migrated from non-surgical treatment to surgery in both the randomized and intent-to-treat groups. There was also a stream of patients who swam in the other direction.

Among the other less-than-ideal aspects of the SPORT trial was the fact that the trial design did not dictate the non-surgical interventions. Although most of the interventions complied with general clinical guidelines, "creating a limited, fixed protocol for non-operative treatment was neither clinically feasible nor generalizable," a situation exacerbated by the "limited evidence regarding efficacy for most non-operative treatments ... and individual variability in response."

The good news-bad news aspect of the study results is that "between-group differences in improvements were consistently in favor of surgery" for all outcomes and follow-up periods, but the authors state that those differences were "small and not statistically significant" with the exception of sciatica severity and self-rated improvement.

Alan Hilibrand, MD, associate professor of orthopedic surgery at Thomas Jefferson University Hospital (Philadelphia) who was involved in the study, told Medical Device Daily that some of the subjects who initially opted for or were assigned to surgery ended up receiving only non-surgical therapies because their symptoms abated while waiting for surgery.

As for the question of which patients should opt for surgery rather than therapy, Hilibrand said that those "who have had symptoms for a long time" might be better candidates for surgery, but the study was not decisive on this score.

The duration of the follow-up was two years, a period that might strike some as stingy. Hilibrand said that while "it would be interesting to see what five and six year outcomes would look like," other health problems can arise that would confuse the question of efficacy. As a consequence, a two-year follow-up is probably "A good point at which to ask 'did the operation work' and what are the benefits of surgical vs. non-surgical treatment?"

The article mentioned the possibility that placebo effect may account for some of the differences in patient-reported outcomes, but Hilibrand said that "placebo effect can work both ways."

"The take-home messages are that there's a role for both surgical and non surgical intervention, and the findings of the study support the general recommendations that when someone presents with a herniated disc, non-surgical treatment is helpful [as a first-line treatment] and when it does not help, surgery is a good alternative."

In an associated editorial penned by David Flum, MD, an associate professor in the department of surgery at the University of Washington Medical Center (Seattle), it was noted that the rate of crossover and the subjectivity of patient reports compromised the value of the study and suggested that a trial with sham surgical procedures is indicated. Flum noted several studies involving sham procedures with little or no differential outcome and said that "an ethical framework for the use of sham surgery has recently been proposed."

"Given the large number of patients potentially exposed to the risks of these [interventional] strategies, a sham surgical trial may be the only effective and ethical next step," Flum observed.