Predictability of the effects of facet joint infiltration in the degenerate lumbar spine when assessing MRI scans

BACKGROUND Imaging results are frequently considered as hallmarks of disease by spine surgeons to plan their future treatment strategy. Numerous classification systems have been proposed to quantify or grade lumbar magnetic resonance imaging (MRI) scans and thus objectify imaging findings. The clinical impact of the measured parameters remains, however, unclear. To evaluate the pathological significance of imaging findings in patients with multisegmental degenerative findings, clinicians can perform image-guided local infiltrations to target defined areas such as the facet joints. The aim of the present retrospective study was to evaluate the correlation of MRI facet joint degeneration and spinal stenosis measurements with improvement obtained by image-guided intraarticular facet joint infiltration. METHODS Fifty MRI scans of patients with chronic lumbar back pain were graded radiologically using a wide range of classification and measurement systems. The reported effect of facet joint injections at the site was recorded, and a comparative analysis performed. RESULTS When we allocated patients according to their reported pain relief, 27 showed no improvement (0-30%), 16 reported good improvement (31-75%) and 7 reported excellent improvement (> 75%). MRI features assessed in this study did, however, not show any relevant correlation with reported pain after facet joint infiltration: Values for Kendall's tau ranged from τ = - 0.190 for neuroforaminal stenosis grading as suggested by Lee, to τ = 0.133 for posterior disc height as proposed by Hasegawa. CONCLUSION Despite the trend in evidence-based medicine to provide medical algorithms, our findings underline the continuing need for individualised spine care that, along with imaging techniques or targeted infiltrations, includes diagnostic dimensions such as good patient history and clinical examination to formulate a diagnosis. TRIAL REGISTRATION ClinicalTrials.gov , NCT03308149 , retrospectively registered October 2017.