Research Article: Diagnosing Discogenic Low Back Pain Associated with Degenerative Disc Disease Using a Medical Interview

Date Published: November 7, 2016

Publisher: Public Library of Science

Author(s): Juichi Tonosu, Hirohiko Inanami, Hiroyuki Oka, Junji Katsuhira, Yuichi Takano, Hisashi Koga, Yohei Yuzawa, Ryutaro Shiboi, Yasushi Oshima, Satoshi Baba, Sakae Tanaka, Ko Matsudaira, Gayle E. Woloschak.

http://doi.org/10.1371/journal.pone.0166031

Abstract

To evaluate the usefulness of our original five questions in a medical interview for diagnosing discogenic low back pain (LBP), and to establish a support tool for diagnosing discogenic LBP.

The degenerative disc disease (DDD) group (n = 42) comprised patients diagnosed with discogenic LBP associated with DDD, on the basis of magnetic resonance imaging findings and response to analgesic discography (discoblock). The control group (n = 30) comprised patients with LBP due to a reason other than DDD. We selected patients from those who had been diagnosed with lumbar spinal stenosis and had undergone decompression surgery without fusion. Of them, those whose postoperative LBP was significantly decreased were included in the control group. We asked patients in both groups whether they experienced LBP after sitting too long, while standing after sitting too long, squirming in a chair after sitting too long, while washing one’s face, and in the standing position with flexion. We analyzed the usefulness of our five questions for diagnosing discogenic LBP, and performed receiver operating characteristic (ROC) curve analysis to develop a diagnostic support tool.

There were no significant differences in baseline characteristics, except age, between the groups. There were significant differences between the groups for all five questions. In the age-adjusted analyses, the odds ratios of LBP after sitting too long, while standing after sitting too long, squirming in a chair after sitting too long, while washing one’s face, and in standing position with flexion were 10.5, 8.5, 4.0, 10.8, and 11.8, respectively. The integer scores were 11, 9, 4, 11, and 12, respectively, and the sum of the points of the five scores ranged from 0 to 47. Results of the ROC analysis were as follows: cut-off value, 31 points; area under the curve, 0.92302; sensitivity, 100%; and specificity, 71.4%.

All five questions were useful for diagnosing discogenic LBP. We established the scoring system as a support tool for diagnosing discogenic LBP.

Partial Text

Low back pain (LBP) affects most adults at some point in their lives. In the last decade, LBP was continuously found to be the top leading cause of years lived with disability globally [1]. As in many industrialized countries, LBP is one of the most common health disabilities in Japan. In a population-based survey, the lifetime and 4-wk LBP prevalence were 83% and 36%, respectively [2].

Patients’ average age was 53.9 years in the DDD group and 71.1 years in the control group. The ratio of age ≥65 years was 16.7% in the DDD group and 30.1% in the control group. There was a significant difference in age between the DDD and control groups (p < 0.0001 and p = 0.0002, respectively). However, there were no significant differences in the other baseline characteristics such as sex, BMI, smoking habit, NRS score, and ODI score. There were significant differences between the groups for each item of the medical interview about LBP after sitting too long (p < 0.0001), LBP while standing after sitting too long (p < 0.0001), squirming in a chair after sitting too long (p = 0.011), LBP while washing one’s face (p < 0.0001), and LBP in standing position with flexion (p < 0.0001) (Table 1). We examined five items of our medical interview regarding discogenic LBP. We hypothesized and defined discogenic LBP as a degenerated disc on MRI and response to a discoblock used for the disc suggestive of LBP. In accordance with our hypotheses that discogenic LBP exists and that a positive response to a discoblock indicates discogenic LBP, all five items of our medical interview about LBP (i.e., LBP after sitting too long, LBP while standing after sitting too long, squirming in a chair after sitting too long, LBP while washing one’s face, and LBP in standing position with flexion) were useful for diagnosing discogenic LBP associated with DDD. We can diagnose discogenic LBP in all cases if four or five of the five items of the medical interview are positive, and in some cases, if three of five items are positive.   Source: http://doi.org/10.1371/journal.pone.0166031