Study design: Systematic review OBJECTIVE.: The aim of the study was to investigate whether magnetic resonance imaging (MRI) findings change over a relatively short period of time (<1 yr) in people with low back pain (LBP) or sciatica. We also investigated whether there was an association between any change in MRI findings and change in clinical outcomes.
Summary of background data: MRI offers the potential to identify possible pathoanatomic sources of LBP and/or sciatica; however, the clinical importance of MRI findings remains unclear. Little is known about whether lumbar MRI findings change over the short term and if so whether these changes are associated with changes in clinical outcomes.
Methods: Medline, EMBASE, and CINAHL databases were searched. Included were cohort studies that performed repeat MRI scans within 12 months in patients with LBP and/or sciatica. Data on study characteristics and change in MRI findings were extracted from included studies. Any data describing associations between change in MRI findings and change in clinical outcomes were also extracted.
Results: A total of 12 studies met the inclusion criteria and were included in the review. Pooling was not possible due to heterogeneity of studies and findings. Seven studies reported on changes in disc herniation and reported 15% to 93% of herniations reduced or disappeared in size. Two studies reported on changes in nerve root compression and reported 17% to 91% reduced or disappeared. Only one study reported on the association between change in MRI findings and change in clinical outcomes within 1 year, and found no association.
Conclusion: This review found moderate evidence that the natural course of herniations and nerve root compression is favorable over a 1-year period in people with sciatica or LBP. There is a lack of evidence on whether other MRI findings change, and whether changes in MRI findings are associated with changes in clinical outcomes.
Level of evidence: 1.