Therapeutic Effectiveness of Lumbar Medial Branch Block and Lumbar Intra-Articular Facet Injections: A Propensity-Matched Cohort Study.

BACKGROUND

Chronic low back pain is a prevalent condition that is treated commonly with radiofrequency neurotomy (RFN) after diagnostic targeting with medial branch blocks (MBB) or intra-articular (IA) injection.

PURPOSE

We evaluated the long-term therapeutic value of MBB and IA injection of steroids for relief from chronic low back pain beyond the current diagnostic utility.

METHODS AND OUTCOME MEASURES

This was a retrospective propensity-matched cohort study from a single physician injection census at a tertiary care hospital. A total of 460 patients receiving MBB (n=383) or IA injection (n=77) in 2013-2020 were included. Primary outcome measures were patient-reported outcomes (PROs) at the time of injection, and follow-up at three and six months with the Numerical Rating Scale (NRS), PRO Measurement Information System (PROMIS)-Mental Health (MH), PROMIS-Physical Health (PH), and the Patient Health Questionnaire (PHQ)-9 scores. The same PROs at the one-year follow-up were the secondary outcome measures. Propensity weighting was performed to balance MBB and IA injection groups over several demographic and clinical categories.

RESULTS

Significant improvements in NRS (p=<0.001) were reported at the three-month, six-month, and one-year follow-ups, while significant improvements in PROMIS-PH scores (p=0.015) were identified at three and six months post injection.

CONCLUSIONS

Our results suggest that MBB and IA injection have potential therapeutic benefits for chronic low back pain for at least six months post injection. These results suggest that there is value in these diagnostic modalities therapeutically beyond the acute time frame. These results lay the groundwork for additional investigations into treatment options for patients affected by chronic low back pain.