Comparing Iovera cold nerve‑freezing versus radiofrequency heat treatment for chronic lumbar facet-related low back pain

Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for participation:

* Subjects at least 18 years of age at Screening
* Primary complaint of axial low-back pain suggestive of bilateral facet joint involvement (i.e., facet mediated CLBP) by evidence of provocative testing (e.g., axial loading, paraspinal tenderness)
* Low back pain is chronic (i.e., ≥ 3 months' duration)
* Low back pain is moderate to severe (score of ≥ 5 to ≤ 9) on the 0 to 10 NRS at Screening
* Low back pain causes functional impairment (≥ 30% on ODI) at Screening
* Successful trial of two diagnostic medial branch blocks consisting of two positive blocks with local anesthetic only (i.e., no steroids) that results in at least 80% relief of primary (index) pain for the duration of the local anesthetic used
* Failure of at least three months of conservative non-operative therapy (e.g., physical therapy, chiropractic care, sleep hygiene, weight loss, spinal injections, NSAIDs, physician-directed exercise program or other appropriate analgesics)
* Able to provide informed consent, adhere to the study visit schedule, and complete all study assessment

Exclusion Criteria:

Subjects who meet any of the following exclusion criteria will not be eligible for participation in this study:

* Active workers' compensation, personal injury, Social Security disability insurance (SSDI), or other litigation/compensation related to the spine
* Serious spinal disorders (verified on magnetic resonance imaging (MRI)) that may impact outcomes, including any of the following:

  1. Suspected cauda equina syndrome (e.g., bowel/bladder dysfunction)
  2. Infection
  3. Tumor
  4. Traumatic fracture
  5. Systemic inflammatory spondyloarthropathy
  6. Lumbar radiculopathy/radiculitis (i.e., root irritation and deficit)
  7. Neurogenic claudication Prior lumbar spinal fusion surgery at the intended treatment levels
* Comorbidity that, in the judgment of the Investigator, may affect the subject's ability to participate in the study including lumbar radiculopathy and neuropathic pain disorder
* Currently pregnant, nursing, or planning to become pregnant during the study
* Known contraindication to study device, including any of the following:

  1. Cryoglobulinemia
  2. Paroxysmal cold hemoglobinuria
  3. Cold urticaria
  4. Raynaud's disease
  5. Open and/or infected wounds at or near the treatment site
  6. Coagulopathy
* Severe chronic pain disorder that in the opinion of the investigator may impact study outcomes
* Presence of any of the following:

  1. Spinal neurostimulator
  2. Intrathecal analgesic drug pump
  3. Cardiac implantable device
* Current manifestation of poorly controlled mental illness or catastrophizing that in the opinion of the investigator may meaningfully impact treatment outcomes, including any of the following:

  1. Mood disorder (e.g., depression, bipolar)

     Patient Health Questionnaire (PHQ-9) ≥ 12 at Screening
  2. Psychotic disorder (e.g., schizophrenia)
  3. Catastrophizing

Patient Catastrophizing Scale (PCS) score \> 30 at Screening

* Subject received other spine intervention/therapies in the 30 days prior to block administration (e.g., spinal injections, minimally invasive therapies, surgical therapies) at the intended lumbar treatment levels
* Subject received radiofrequency ablation in the low back region ≤ 6 months before study enrollment at the intended lumbar treatment levels
* Pain relief following diagnostic medial branch blocks lasted longer than the duration of the local anesthetic used (i.e., \> 24 hours)

  1. History, suspicion, or clinical manifestation of:
  2. Alcohol abuse or dependence
  3. Illicit drug use
* Opioid abuse or dependence (≥40 mg medication PO/day in past 30 days)
* Given the COVID-19 pandemic, the subject must be medically fit/cleared for surgery by the investigator. If there is a concern about a subject's recent or potential exposure to COVID-19, or if the subject is not medically fit/cleared for surgery due to suspected COVID-19 illness/symptoms (or other serious illness), the subject must be excluded.