Spinal surgeons do not agree about which tests to use to predict success of spinal fusion surgery for chronic low back pain, study shows


According to a study in BMJ Open, there is a lack of consensus among spinal surgeons on the appreciation and use of predictive tests for selecting patients with chronic low back pain for spinal fusion surgery. Lead researcher Paul Willems (Department of Orthopaedics, Research School Caphri, Maastricht University Medical Center, The Netherlands) and his colleagues state that this lack of consensus is due to a lack of evidence in this area.

Willems et al surveyed orthopaedic surgeons and neurosurgeons from the Dutch Spine Society about their surgical treatment strategy for the management of low back pain. Of the 62 respondents analysed, 41 (71%) were found to have extensive clinical experience.


Respondents were asked about the value of several predictive tests for the outcome of spinal fusion in patients with chronic low back pain. Aside from the respondents’ view of MRI, they did not appear to reach a consensus about the benefits of these tests. Willems et al reported that, mainly, orthopaedic surgeons rather than neurosurgeons saw provocative discography as a valid predictive test (21 of 46 vs 2 of 16, respectively). They added: “Spinal surgeons working in a general hospital appeared to believe more in the test (20 of 43) than academic surgeons did (3 of 18).” Discography was the only predictive test in which clinical discipline appeared to have an influence, and years of clinical experience was not found to influence opinion on any test.


Respondents were also asked to review 11 prognostic factors (eg, psychological profile, works status) and state to what extent they influence their clinical decision making in the treatment of chronic low back pain. There was no consensus for seven of these factors (<70% uniformity of opinion). For example, 46.7% agreed that the patient’s work status affected outcome, 27.4% said it had a neutral effect on outcome and 25.9% disagreed that it had an effect on outcome.


However, more than 70% did say that they would perform fusion surgery on a patient who was more than 60 years of age. Again, years of clinical experience or speciality did not seem affect the respondents’ view of prognostic factors.


Additionally, the researchers found some disparity between what is in the literature and what the respondents did in practice. While the literature does not recommend fusion surgery before the patient has had two years of conservative therapy, 63% of surgeons in the study thought that fusion surgery could be considered even when the patient had less than one year’s conservative therapy. Also, despite obesity being reported in the literature as being significantly associated with major complications (eg, thromboembolism), less than half of the surgeons (47%) in the survey consistently referred patients to a dietician and 24% would operate on morbidly obese patients.


As the lack of consensus observed in the survey could not be explained by clinical experience or clinical discipline, Willems et al stated it was “more likely that the observed heterogeneity of opinion reflects the absence of consistent high-quality evidence for the validity of prognostic factors and predictive tests.”


They therefore added that future research is needed to identify a subgroup of patients who are likely to benefit from spinal fusion surgery. They wrote:  “A reliable prediction of surgical outcome, combined with the implementation of individual patient factors, would enable the instalment of uniform clinical guidelines for surgical decision making. Only if the results of fusion can be improved by better patient selection, could there be a role for spinal fusion as the treatment of choice for a particular subgroup of patients with chronic low back pain.”


Willems told Spinal News International: “The present survey consistently showed a lack of consensus among spinal surgeons. Decision making for fusion surgery in the treatment of chronic low back pain does not have a uniform evidence base in clinical practice. Recently, we performed a systematic review on the accuracy of tests that predict the result of fusion for low back pain. Our review, which has been submitted for publication, showed that best evidence does not support the use of current tests for patient selection in clinical practice. No subset of patients with chronic low back pain could be identified for whom spinal fusion is a predictable and effective treatment. This highlights once more that we will not be able to install uniform clinical guidelines as long as there is no consistent high quality evidence for the validity of prognostic factors and predictive tests to select and operate on only those patients with chronic low back pain who will benefit from fusion surgery.”