The value of a pantaloon cast test in surgical decision making for chronic low back pain patients: a systematic review of the literature supplemented with a prospective cohort study

Abstract

The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, chi (2 )test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery.

Clinical decision making in spinal fusion for chronic low back pain. Results of a nationwide survey among spine surgeons

“…This resembles conflicting reports from the literature claiming that the test is not predictive of fusion outcome26 or that only in highly selected patient groups the pantaloon cast test may be of value 27…”

Safety and Efficacy of Anterior Lumbar Interbody Fusion for Discogenic Chronic Low Back Pain in a Short-stay Setting: Data From a Prospective Registry

“…A range of prognostic tools have been tested over the years. Apart from failed long-term conservative treatment, the PCT has shown to be the single most efficient prognostic test for outcome after surgery for CLBP, and has been independently verified to be so [1,8]. A positive PCT is especially predictive in patients with single-level DDD without prior surgery [1,8].…”

“…Apart from failed long-term conservative treatment, the PCT has shown to be the single most efficient prognostic test for outcome after surgery for CLBP, and has been independently verified to be so [1,8]. A positive PCT is especially predictive in patients with single-level DDD without prior surgery [1,8]. This effect may be explained in two ways: The PCT simulates a bony fusion by stabilizing the lumbar vertebrae, and the willingness to endure an uncomfortable pantaloon cast for two weeks indicating a certain “last resort” motivation.…”

“…To be considered for surgical treatment, patients had to have completed ≥6 months of unsuccessful conservative treatment. Unless failed back surgery syndrome (FBSS) after at least two prior surgeries at the index level was present, patients had to undergo pantaloon cast testing (PCT) for two weeks, with a ≥50% improvement in back pain over at least 14 days to be considered for surgery [1,8,16]. Provocative discography and disco-block were not regularly used [1,17-21].…”

“…The surgical treatment of CLBP due to DDD through lumbar fusion has been controversial, as it has been suggested that surgical therapy is not necessarily better than conservative therapy in the general patient population [7]. However, it has been observed that through thorough patient selection, the chances of successful treatment with interbody fusion are substantially improved, indicating that there are in fact subsets of patients that truly profit from surgery [1,8]. Especially a positive outcome of the Pantaloon Cast Test (PCT), a cast worn for a certain period of time to increase stability and therefore imitate a spinal fusion, has served as a suitable prognostic test in determining likely successful surgery in patients who have not improved through long-term conservative therapy [1,8].…”