Objective: To determine the clinical factors associated with the success and failure of radiofrequency denervation of the lumbar facet joints.
Methods: Clinical data were garnered from 3 academic medical centers on 192 patients with low back pain who underwent radiofrequency denervation after a positive response to diagnostic blocks. Success was defined as >/=50% pain relief lasting at least 6 months. Factors evaluated for their association with outcome included duration of pain, opioid use, symptom location, paraspinal tenderness, pain exacerbated by extension/rotation (ie, facet loading), MRI abnormalities, diabetes, smoking, scoliosis, obesity, prior surgery and levels treated.
Results: The only factor associated with a successful outcome was paraspinal tenderness. Variables that correlated with treatment failure were 'facet loading,' long duration of pain, and previous back surgery.
Conclusions: It is counterproductive to use 'facet loading' as the sole basis for choosing patients for facet interventions. In patients at high risk for treatment failure, taking additional steps to reduce the rate of false-positive screening blocks may improve outcomes.