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Does the Location of Low Back Pain Predict Its Source?
Author(s) -
DePalma Michael J.,
Ketchum Jessica M.,
Trussell Brian S.,
Saullo Thomas R.,
Slipman Curtis W.
Publication year - 2011
Publication title -
pmandr
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.617
H-Index - 66
eISSN - 1934-1563
pISSN - 1934-1482
DOI - 10.1016/j.pmrj.2010.09.006
Subject(s) - medicine , sacroiliac joint , interquartile range , low back pain , facet joint , facet (psychology) , back pain , surgery , lumbar , pathology , psychology , social psychology , big five personality traits , alternative medicine , personality
Objective To evaluate the predictive utility of the pattern of low back pain (LBP) in detecting the source of LBP as internal disk disruption (IDD), facet joint pain (FJP), or sacroiliac joint pain (SIJP). Design Retrospective chart review. Setting University spine center. Patient sample A total of 170 cases from 156 patients presenting with LBP whose low back disorder was definitively diagnosed. The mean age was 54.4 years (SD, 16.2) and median duration of LBP was 12 months (interquartile ranges, 6‐32). Methods Charts of consecutive LBP patients who underwent definitive diagnostic spinal procedures including provocation diskography, facet joint blocks, and sacroiliac joint blocks were retrospectively reviewed. Each patient with LBP was queried as to the exact location of their LBP: midline, defined as in‐line with the spinous processes, and/or paramidline, defined as lateral to 1 fingerbreadth adjacent to the midline. Outcome Measures In patients with a definitive diagnosis for the source of LBP, the proportion of each diagnosed source of pain was calculated. χ 2 tests were used to identify differences in the percentages of midline and paramidline LBP among the groups of patients testing positive for IDD, FJP, or SIJP. Diagnostic measures of sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and likelihood ratios of positive and negative tests using the presence/absence of midline and paramidline pain for the diagnosis of IDD, FJP, and SIJP were estimated. Results With cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ 2 = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). In cases of IDD, significantly lower percentages of patients reported paramidline pain (67.3%; χ 2 = 16.1, df = 2, P = .0003) as compared with cases of FJP (95.0%) or SIJ (96.0%). In cases of IDD, significantly greater percentages of patients reported midline LBP (95.8%; χ 2 = 101.4, df = 2, P < .0001) as compared with cases of FJP (15.4%) or SIJP (12.9%). The specificity of midline LBP for IDD, FJP, and SIJP was 74.8% (95% CI = 65.0%‐82.9%), 28.0% (20.1%‐37.0%), and 36.0% (28.0%‐44.5%), respectively. The negative predictive value of paramidline LBP for IDD, FJP, and SIJP was 29.2% (95% CI = 12.6%‐51.1%), 91.7% (73.0%‐99.0%), and 95.8% (78.9%‐99.9%). The diagnostic accuracy of midline LBP for IDD, FJP, and SIJP was 83.5%, 24.1%, and 31.8%, respectively. Conclusions The presence of midline LBP increases the probability of lumbar IDD and reduces the probability of symptomatic FJ and SIJ dysfunction. The presence of isolated paramidline LBP increases the probability of symptomatic FJ or SIJ but mildly reduces the likelihood of lumbar IDD.