Frequency of Positive Lumbosacral MRI Results in Patients Ton-traumaticlow Back Pain Based on the Specialty of the Referring Physician

Low back pain (LBP) is the most common musculoskeletal disorder and an important cause of disability. Although imaging techniques have been developed for LBP treatment, they have not been successful to improve its prognosis. Although MRI is necessary for diagnosing some diseases, their economic burden on the health system is high. It is challenging to set appropriate guidelines for the correct use of imaging methods in developing countries due to limited capacity and resources. This study aims to investigate the frequency of the positive results of lumbosacral MRI in non-traumatic patients aged >18 years with LBP.

This retrospective descriptive-analytical study was conducted from August 2016 to September 2017. The inclusion criteria were: having non-traumatic LBP, age >18 years, completeness file of medical records file, and having knowledge of the specialty of the referring physician. The MRI findings and demographic information including age and gender were collected from the imaging information system of Al-Zahra Hospital in Isfahan, Iran.MRI findings including disc herniation, spinal canal stenosis, spondylosis and spondylolisthesis were considered as the positive result. We also called the patients and asked about their need for medical or surgical intervention. The frequency of positive lumbosacral MRI results were estimated based on the specialty of the referring physician and the results were then compared between different groups. To confirm the validity and reliability of the data collection tool, all MRI images were performed with one single imaging protocol and the reports were made by the same radiologist.The final collected data were entered into SPSS software, version. All quantitative data were reported as Mean±SD and the qualitative data were reported using frequency and percentage. Chi-squared test, independent t-test and one-way analysis of variances (ANOVA) were used to determine if there was a significant difference in the frequency of positive MRI findings among the different groups based on the specialty of the referring physician. P<0.05 was statistically significant.

Of 335 participants, 145(43.3%) were male and 190(56.7%) were female. Their mean age was 43.9±15.4 years. Among the referring physicians, 139(41.5%) were neurosurgeons, 114(34%) were orthopedists, 61(18.2%) were neurologists, and 21(6.3%) were physical medicine specialists. It was reported that 291(87.1%) of patients had no spinal canal stenosis, while 43(12.9%) had this pathology. More than 95% of patients had no any spinal deformity and spondylolisthesis, while 52.2% had spondylosis. Moreover, 201 cases (60%) had no disc herniation; among the reminding cases, 104(31%) had disc protrusion, 27(8.1%) had disc extrusion, and 3(0.9%) had disc sequestration.The MRI results of 335 patients based on the specialty of the referring physician are shown in Table 1. There was no significant difference among different specialties in the frequency of positive MRI results (P>0.05).Since the number of the physical medicine specialists was low and could affect the significance of the result for this group, data analysis was conducted one more time after removing this group. Based on the results, spinal canal stenosis was observed in 40 patients, of which 62.5% were related to neurosurgery group, 22.5% for orthopedics group, and 15% for neurology group. The difference was statistically significant (P=0.044). Regarding other positive MRI findings, no statistically significant difference was observed among different specialties of physicians. Table 2 shows the frequency of LBP managements (surgical and non-surgical) based on the specialty of the referring physician. Regarding the relationship between the LBP management in patients and the specialty of the referring physician, the correlation coefficient was obtained 0.227 which was statistically significant (P=0.032).

There is no significant difference in frequency of positive lumbosacral MRI results in patients with LBP based on the specialty of the referring physician.