title: Long-Term Function, Pain and Medication Use Outcomes of Radiofrequency Ablation for Lumbar Facet Syndrome.
abstract: OBJECTIVE
  Radiofrequency ablation (RFA) of the medial branch nerves for facet-mediated low back pain demonstrates clinical benefit for 6-12 months and possibly up to 2 years. This study investigated function, pain, and medication use outcomes of RFA for lumbar facet syndrome in a cohort with long-term follow-up.
  
  
  METHODS
  Individuals evaluated in a tertiary academic pain practice between January, 2007-December, 2013, 18-60 years of age, with a clinical and radiologic diagnosis of lumbar facet syndrome, who underwent ≥1set of diagnostic medial branch blocks with resultant >75% pain relief and subsequent RFA were included. Outcomes measured were the proportion of individuals who reported ≥50% improvement in function, ≥50% improvement in pain; change in median NRS pain score, daily morphine equivalent consumption (DME), Medication Quantification Scale III (MSQ III) score and procedure complications.
  
  
  RESULTS
  Sixty-two consecutive individuals with a median age and 25%-75% interquartile range (IQR) of 34 years (35, 52) met inclusion criteria. Seven individuals were lost to follow-up. Duration of pain was <2 years in 42%, 2-5 years in 40%, >5 years in 18% of individuals. Median duration of follow-up was 39 months (16, 60). Function and pain improved by ≥50% in 58% (CI 45%, 71%) and 53% (CI 40%, 66%) of individuals, respectively. The median reduction in MQS III score was 3.4 points (0, 8.8). No complications occurred in this cohort.
  
  
  CONCLUSIONS
  This study demonstrates a durable treatment effect of RFA for lumbar facet syndrome at long-term follow-up, as measured by improvement in function, pain, and analgesic use.
authors.affiliation: The Rehabilitation Institute of Chicago/Northwestern University Feinberg School of Medicine, Department of Physical Medicine and Rehabilitation, USA.
authors.forename: Zachary L
authors.initials: ZL
authors.lastname: McCormick
authors.affiliation: The Rehabilitation Institute of Chicago/Northwestern University Feinberg School of Medicine, Department of Physical Medicine and Rehabilitation, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Marshall
authors.affiliation: Northwestern University Feinberg School of Medicine, Department of Anesthesiology, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Walker
authors.affiliation: Northwestern University Feinberg School of Medicine, Department of Anesthesiology, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: McCarthy
authors.affiliation: Northwestern University Feinberg School of Medicine, Department of Anesthesiology, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Walega
keywords: Denervation; Low back pain; Opioid analgesics; Zygapophyseal joint