Cryoneurolysis for Facet Mediated Chronic Low Back Pain

This is a single-center, randomized, pilot study in adult subjects with facet mediated CLBP. Thirty (30) subjects are planned for initial enrollment and will be randomized 1:1 to receive ioveraº medial branch cryoneurolysis or radiofrequency ablation.

This study is designed to determine if a full efficacy RCT can be successfully conducted using the procedures and protocols described in the current pilot study protocol, or if protocol modifications are necessary before moving forward with a full efficacy RCT. Furthermore, the study will assess the feasibility of the outcome measurements employed, construct a foundation for sample size calculation, and the acceptability/practicality of conducting the full efficacy RCT.

Randomization to treatment groups according to the randomization assignment will be performed on the day of treatment. The treatment groups are:

• Group 1: subjects will receive iovera° cryoneurolysis to the medial branch nerves of the lumbar spine
• Group 2: subjects will receive RFA to the medial branch nerves of the lumbar spine

Inclusion criteria

• Male or female volunteers, at least 18 years of age at screening
• Primary complaint of axial low-back pain suggestive of unilateral or bilateral facet joint involvement (i.e., facet mediated CLBP)
• Low back pain is chronic (i.e., > 3 months' duration)
• Low back pain score of ≥ 4 (i.e., moderate pain) on the 0 to 10 NRS or functional impairment 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 50% relief of primary (index) pain for the duration of the local anesthetic used or history of a positive response to prior radiofrequency treatment (i.e., ≥ 6 months prior to enrollment)
• Failure of at least three months of conservative non-operative therapy (e.g., physical therapy, chiropractic care, spinal injections, NSAIDs or other appropriate analgesics),
• Able to provide informed consent, adhere to the study visit schedule, and complete all study assessments

Exclusion criteria

• 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:

• Suspected cauda equina syndrome (e.g., bowel/bladder dysfunction)
• Infection
• Tumor
• Traumatic fracture
• Systemic inflammatory spondyloarthropathy
• Lumbar radiculopathy/radiculitis (i.e., root irritation and deficit)
• Neurogenic claudication
• Prior lumbar spinal fusion surgery
• 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 devices, including any of the following:

• Cryoglobulinemia
• Paroxysmal cold hemoglobinuria
• Cold urticaria
• Raynaud's disease
• Open and/or infected wounds at or near the treatment site
• Coagulopathy
• 3.5-inch needle cannot be used in the low back region because of habitus
• Severe chronic pain disorder that in the opinion of the investigator may impact postsurgical outcomes
• Presence of any of the following:

• Spinal neurostimulator
• Intrathecal analgesic drug pump
• Current manifestation of poorly controlled mental illness that in the opinion of the investigator may meaningfully impact treatment outcomes, including any of the following:

• Mood disorder (e.g., major depression, bipolar)
• Psychotic disorder (e.g., schizophrenia)
• Subject received other spine intervention/therapies in the 30 days prior to block administration (e.g., spinal injections, minimally invasive therapies, surgical therapies)
• Subject received radiofrequency ablation in the low back region ≤ 6 months before study enrollment
• History, suspicion, or clinical manifestation of:

• Alcohol abuse or dependence
• Illicit drug use
• Opioid abuse or dependence (≥40 mg MED PO/day in past 30 days) Given the COVID-19 pandemic, the subject must be medically fit/cleared for treatment 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 treatment due to suspected COVID-19 illness/symptoms (or other serious illness), the subject must be excluded per Exclusion criterion #4.