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Acta Orthop Suppl. 2013 Feb;84(349):1-35. doi: 10.3109/17453674.2012.753565.
Decision making in surgical treatment of chronic low back pain: the performance of prognostic tests to select patients for lumbar spinal fusion.
Willems P1.
Author information
Abstract
Chronic low back pain (CLBP) is one of the main causes of disability in the western world with a huge economic burden to society. As yet, no specific underlying anatomic cause has been identified for CLBP. Imaging often reveals degenerative findings of the disc or facet joints of one or more lumbar motion segments. These findings, however, can also be observed in asymptomatic people. It has been suggested that pain in degenerated discs may be caused by the ingrowth of nerve fibers into tears or clefts of the annulus fibrosus or nucleus pulposus, and by reported high levels of pro-inflammatory mediators. As this so-called discogenic pain is often exacerbated by mechanical loading, the concept of relieving pain by spinal fusion to stabilise a painful spinal segment, has been developed. For some patients lumbar spinal fusion indeed is beneficial, but its results are highly variable and hard to predict for the individual patient. To identify those CLBP patients who will benefit from fusion, many surgeons rely on tests that are assumed to predict the outcome of spinal fusion. The three most commonly used prognostic tests in daily practice are immobilization in a lumbosacral orthosis, provocative discography and trial immobilization by temporary external transpedicular fixation. Aiming for consensus on the indications for lumbar fusion and in order to improve its results by better patient selection, it is essential to know the role and value of these prognostic tests for CLBP patients in clinical practice. The overall aims of the present thesis were: 1) to evaluate whether there is consensus among spine surgeons regarding the use and appreciation of prognostic tests for lumbar spinal fusion; 2) to verify whether a thoracolumbosacral orthosisis (TLSO) truly minimises lumbosacral motion; 3) to verify whether a TLSO can predict the clinical outcome of fusion for CLBP; 4) to assess whether provocative discography of adjacent segments actually predicts the long-term clinical outcome fusion; 5) to determine the incidence of postdiscography discitis, and whether there is a need for routine antibiotic prophylaxis; 6) to assess whether temporary external transpedicular fixation (TETF) can help to predict the outcome of spinal fusion; 7) to determine the prognostic accuracy of the most commonly used tests in clinical practice to predict the outcome of fusion for CLBP. The results of a national survey among spine surgeons in the Netherlands were presented in Study I. The surgeons were questioned about their opinion on prognostic factors and about the use of predictive tests for lumbar fusion in CLBP patients. The comments were compared with findings from the prevailing literature. The survey revealed a considerable lack of uniformity in the use and appreciation of predictive tests. Prognostic factors known from the literature were not consistently incorporated in the surgeons' decision making process either. This heterogeneity in strategy is most probably caused by the lack of sound scientific evidence for current predictive tests and it was concluded that currently there is not enough consensus among spine surgeons in the Netherlands to create national guidelines for surgicaldecision making in CLBP. In Study II, the hypothesized working mechanism of a pantaloon cast (i.e., minimisation of lumbosacral joint mobility) was studied. In patients who were admitted for a temporary external transpedicular fixation test (TETF), infrared light markers were rigidly attached to the protruding ends of Steinman pins that were fixed in two spinal levels. In this way three-dimensional motion between these levels could be analysed opto-electronically. During dynamic test conditions such as walking, a plaster cast, either with or without unilateral hip fixation, did not significantly decrease lumbosacral joint motion. Although not substantiated by sound scientific support, lumbosacral orthoses or pantaloon casts are often used in everyday practice as a predictor for the outcome of fusion. A systematic review of the literature supplemented with a prospective cohort study was performed (Study III) in order to assess the value of a pantaloon cast in surgical decision-making. It appeared that only in CLBP patients with no prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative treatment. In patients with prior spine surgery the test is of no value. It is believed by many spine surgeons that provocative discography, unlike plain radiographs or magnetic resonance imaging, is a physiologic test that can truly determine whether a disc is painful and relevant in a patient's pain syndrome, irrespective of the morphology of the disc. It has been suggested that in order to achieve a successful clinical outcome of lumbar fusion, suspect discs should be painful and adjacent control discs should elicit no pain on provocative discography. For this reason, a cohort of patients in whom the decision to perform lumbar fusion was based on an external fixation (TETF) trial, was analysed retrospectively in Study IV. The results of preoperative discography of solely the levels adjacent to the fusion were compared with the clinical results after spinal fusion. It appeared that in this select group of patients the discographic status of discs adjacent to a lumbar fusion did not have any effect on the clinical outcome. The most feared complication of lumbar discography is discitis. Although low in incidence, this is a serious complication for a diagnostic procedure and prevention by the use of prophylactic antibiotics has been advocated. In search for clinical guidelines, the risk of postdiscography discitis was assessed in Study V by means of a systematic literature review and a cohort of 200 consecutive patients. Without the use of prophylactic antibiotics, an overall incidence of postdiscography discitis of 0.25% was found. To prove that antibiotics would actually prevent discitis, a randomised trial of 9,000 patients would be needed to reach significance. Given the possible adverse effects of antibiotics, it was concluded that the routine use of prophylactic antibiotics in lumbar discography is not indicated. In Study VI, the middle- and long-term results of external fixation (TETF) as a test to predict the clinical outcome of lumbar fusion were studied in a group of back pain patients for whom there was doubt about the indication for surgery. The test included a placebo trial, in which the patients were unaware whether the lumbar segmental levels were fixed or dynamised. Using strict and objective criteria of pain reduction on a visual analogue scale, the TETF test failed to predict clinical outcome of fusion in this select group of patients. Pin track infection and nerve root irritation were registered as complications of this invasive test. It was concluded that in chronic low back pain patients with a doubtful indication for fusion, TETF is not recommended as a supplemental tool for surgical decision-making. In Study VII, a systematic literature review was performed regarding the prognostic accuracy of tests that are currently used in clinical practice and that are presumed to predict the outcome of lumbar spinal fusion for CLBP. The tests of interest were magnetic resonance imaging (MRI), TLSO immobilisation, TETF, provocative discography and facet joint infiltration. Only 10 studies reporting on three different index tests (discography, TLSO immobilisation and TETF) that truly reported on test qualifiers, such as sensitivity, specificity and likelihood ratios, could be selected. It appeared that the accuracy of all prognostic tests was low, which confirmed that in many clinical practices patients are scheduled for fusion on the basis of tests, of which the accuracy is insufficient or at best unknown. As the overall methodological quality of included studies was poor, higher quality trials that include negatively tested as well as positively tested patients for fusion, will be needed. It was concluded that at present, best evidence does not support the use of any prognostic test in clinical practice. No subset of patients with low back pain could be identified, for whom spinal fusion is a reliable and effective treatment. In literature, several studies have reported that cognitive behavioural therapy or intensive exercise programs have treatment results similar to those of spinal fusion, but with considerably less complications, morbidity and costs. As the findings of the present thesis show that the currently used tests do not improve the results of fusion by better patient selection, these tests should not be recommended for surgical decision making in standard care. Moreover, spinal fusion should not be proposed as a standard treatment for chronic low back pain. Causality of nonspecific spinal pain is complex and CLBP should not be regarded as a diagnosis, but rather as a symptom in patients with different stages of impairment and disability. Patients should be evaluated in a multidisciplinary setting or Spine Centre according to the so-called biopsychosocial model, which aims to
identify underlying psychosocial factors as well as biological factors. Treatment should occur in a stepwise fashion starting with the least invasive treatment. The current approach of CLBP, in which emphasis is laid on self-management and empowerment of patients to take an active course of treatment in order to prevent long-term disability and chronicity, is recommended.
Spine (Phila Pa 1976). 2007 May 1;32(10):1094-9; discussion 1100.
Provocative discography and lumbar fusion: is preoperative assessment of adjacent discs useful?
Willems PC1,
Elmans L,
Anderson PG,
van der Schaaf DB,
de Kleuver M.
Author information
Abstract
STUDY DESIGN:
A cohort study of clinical outcomes of lumbar fusion patients with preoperative assessment of adjacent levels by provocative discography.
OBJECTIVE:
To evaluate whether the preoperative status of the adjacent discs, as determined by provocative discography, has an impact on the clinical outcome of lumbar fusion in chronic low back pain (LBP) patients.
SUMMARY OF BACKGROUND DATA:
The results of lumbar fusion in chronic LBP patients vary considerably and are hard to predict. It is believed that degenerative levels adjacent to a fused spinal segment may be a cause of continuing pain. In this respect, it is important to know whether preoperative degenerative or symptomatic adjacent levels have an adverse effect on patient outcomes after lumbar fusion.
METHODS:
In 197 patients with an equivocal indication for lumbar fusion (two thirds were patients with prior spine surgery), the decision for either lumbar fusion or conservative management was determined by a temporary external transpedicular fixation trial. During the diagnostic workup, all patients had undergone provocative discography that included the assessment of the discs adjacent to the intended fusion levels. The individual changes in pain on a visual analog scale, assessed before treatment and at follow-up, and patient satisfaction were the measures of outcome.
RESULTS:
In the 82 patients who underwent a lumbar fusion, no difference in outcome was found between those patients with degenerative or symptomatic discs adjacent to the fusion and those with normal adjacent discs.
CONCLUSION:
In this cohort study of chronic LBP patients with an uncertain indication for lumbar fusion, the preoperative status of adjacent levels as assessed by provocative discography did not appear to be related to the clinical outcome after fusion.
J Spinal Disord Tech. 2002 Jun;15(3):245-51.
Does provocative discography screening of discogenic back pain improve surgical outcome?
Madan S1,
Gundanna M,
Harley JM,
Boeree NR,
Sampson M.
Author information
Abstract
The value of preoperative provocative discography in the setting of discogenic low back pain was investigated by evaluating surgical outcomes. Seventy-three consecutive patients who underwent posterolateral interbody and posterior spinal arthrodesis for discogenic low back pain refractory to nonoperative management were reviewed. Chronologically, the first 41 patients (group A) were indicated without discography, whereas the remaining 32 (group B) had been indicated only if their pain had been reproduced during disc injection. The two groups were similar in demographic, psychometric, and radiologic parameters. Average follow-up time in group A was 2.8 years and in group B it was 2.4 years, both with a 2-year minimum. Using modified Oswestry scoring, group A and group B patients had satisfactory outcomes of 75.6% and 81.2%, respectively. This difference was neither statistically significant nor suggestive. In this study, provocative discography screening did not improve surgical outcomes after circumferential fusion for lumbar discogenic back pain.
