Study design and patient selection
non-radicular, low back pain, pain
This IRB-approved (111315), single-blinded, randomized prospective comparative trial was conducted in a single tertiary academic center within the Department of Physical Medicine and Rehabilitation. Participants were recruited and treated between November 2018 and September 2021. All participants provided written informed consent before undergoing any active treatment interventions. Included were English-speaking adult patients aged ≥21 years, who had (1) unilateral or bilateral axial (non-radicular) low back pain for ≥3 months that had not responded to conservative treatment (physical therapy, oral analgesic agents, and non-invasive adjunctive treatments), (2) 7-day average numeric pain rating score (NPRS) for back pain of 5/10 or greater at baseline evaluation, and (3) had confirmed lumbar facet mediated pain (defined by ≥80% reduction of index pain after dual comparative diagnostic MBBs using 0.5 mL of 0.5% bupivacaine and 4% lidocaine, on respective encounters on separate days, at each of the appropriate medial branches). The MBBs were performed according to Spine Intervention Society guidelines.