Cryoneurolysis for Facet Mediated Chronic Low Back Pain

A Single-center, Randomized, Pilot Study to Assess Iovera° Lumbar Medial Branch Cryoneurolysis vs Lumbar Radiofrequency Ablation 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 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:

1. Male or female volunteers, at least 18 years of age at screening
2. Primary complaint of axial low-back pain suggestive of unilateral or bilateral facet joint involvement (i.e., facet mediated CLBP)
3. Low back pain is chronic (i.e., > 3 months' duration)
4. Low back pain score of ≥ 4 (i.e., moderate pain) on the 0 to 10 NRS or functional impairment at screening
5. 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)
6. Failure of at least three months of conservative non-operative therapy (e.g., physical therapy, chiropractic care, spinal injections, NSAIDs or other appropriate analgesics),
7. Able to provide informed consent, adhere to the study visit schedule, and complete all study assessments

Exclusion Criteria:

1. Active workers' compensation, personal injury, Social Security disability insurance (SSDI), or other litigation/compensation related to the spine

2. 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

3. Prior lumbar spinal fusion surgery

4. 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

5. Currently pregnant, nursing, or planning to become pregnant during the study

6. Known contraindication to study devices, 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

7. 3.5-inch needle cannot be used in the low back region because of habitus

8. Severe chronic pain disorder that in the opinion of the investigator may impact postsurgical outcomes

9. Presence of any of the following:

   1. Spinal neurostimulator
   2. Intrathecal analgesic drug pump

10. Current manifestation of poorly controlled mental illness that in the opinion of the investigator may meaningfully impact treatment outcomes, including any of the following:

    1. Mood disorder (e.g., major depression, bipolar)
    2. Psychotic disorder (e.g., schizophrenia)

11. Subject received other spine intervention/therapies in the 30 days prior to block administration (e.g., spinal injections, minimally invasive therapies, surgical therapies)

12. Subject received radiofrequency ablation in the low back region ≤ 6 months before study enrollment

13. History, suspicion, or clinical manifestation of:

    1. Alcohol abuse or dependence
    2. Illicit drug use
    3. 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.