First-Time Lumbar Medial Branch Radiofrequency Ablation: Patient-Reported Outcomes Measurement Information System as a Metric of Outcome

Abstract

Objective: To investigate the ability of Patient-Reported Outcomes Measurement Information System (PROMIS) to capture the therapeutic effect of first-time medial branch radiofrequency ablation (RFA).

Design: Before-after trial.

Setting: Single academic spine center.

Participants: Patients who underwent first-time medial branch RFA for lumbar facet joint pain identified by dual comparative medial branch block with ≥80% pain relief between January 1, 2015 and September 1, 2019 were identified using procedural billing codes. Charts were reviewed manually to confirm accuracy and strict adherence to the 80% pain relief threshold for each medial branch block. Thirty-nine patients met the criteria and were included in this study (N=39).

Interventions: Medial branch RFA.

Main outcome measures: PROMIS score domains of Depression, Pain Interference, and Physical Function collected pre- and post RFA were compared. Pretreatment scores were within 6 weeks prior to the first medial branch block. Posttreatment scores were between 5 weeks and 6 months after RFA. Paired-sample t test analyses were used to calculate responsiveness to treatment, with significance assigned as P<.05 prior to acquiring data. Effect size was calculated using Cohen's d.

Results: PROMIS domains of Pain Interference and Physical Function demonstrated a statistically significant improvement (P=.004 and P=.017, respectively). The PROMIS domain of Depression did not demonstrate a statistically significant change (P=.12). The effect size was medium (d=-0.43) for Pain Interference, small/medium (d=0.31) for Physical Function, and small (d=-0.12) for Depression.

Conclusions: Medial branch RFA as a treatment for lumbar facet syndrome is associated with a statistical improvement in PROMIS domains of Physical Function and Pain Interference.

Keywords: Low back pain; Patient reported outcome measures; Radiofrequency ablation; Rehabilitation; Zygapophyseal joint.