Cryoneurolysis’ outcome on pain experience (COPE) in patients with low-back pain: study protocol for a single-blinded randomized controlled trial

K. Truong*, K. Meier, L. Nikolajsen, M. W. van Tulder, J. C.H. Sørensen, M. M. Rasmussen

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review


BACKGROUND: Low-back pain, including facet joint pain, accounts for up to 20 % of all sick leaves in DenmarkA proposed treatment option is cryoneurolysis. This study aims to investigate the effect of cryoneurolysis in lumbar facet joint pain syndrome.

METHODS: A single-center randomized controlled trial (RCT) is performed including 120 participants with chronic facet joint pain syndrome, referred to the Department of Neurosurgery, Aarhus University Hospital. Eligible patients receive a diagnostic anesthetic block, where a reduction of pain intensity ≥ 50 % on a numerical rating scale (NRS) is required to be enrolled. Participants are randomized into three groups to undergo either one treatment of cryoneurolysis, radiofrequency ablation or placebo. Fluoroscopy and sensory stimulation is used to identify the intended target nerve prior to administrating the above-mentioned treatments. All groups receive physiotherapy for 6 weeks, starting 4 weeks after treatment. The primary outcome is the patients' impression of change in pain after intervention (Patient Global Impression of Change (PGIC)) at 4 weeks follow-up, prior to physiotherapy. Secondary outcomes are a reduction in low-back pain intensity (numeric rating scale) and quality of life (EQ-5D, SF-36) and level of function (Oswestry Disability Index), psychological perception of pain (Pain Catastrophizing Scale) and depression status (Major Depression Inventory). Data will be assessed at baseline (T0), randomization (T1), day one (T2), 4 weeks (T3), 3 (T4), 6 (T5) and 12 months (T6).

DISCUSSION: This study will provide information on the effectiveness of cryoneurolysis vs. the effectiveness of radiofrequency ablation or placebo for patients with facet joint pain, and help to establish whether cryoneurolysis should be implemented in clinical practice for this patient population.

TRIAL REGISTRATION: The trial is approved by the ethical committee of Central Jutland Denmark with registration number 1-10-72-27-19 and the Danish Data Protection Agency with registration number 666,852. The study is registered at with the ID number NCT04786145 .

Original languageEnglish
Article number458
Pages (from-to)1-9
Number of pages9
JournalBMC musculoskeletal disorders
Issue number1
Early online date19 May 2021
Publication statusPublished - Dec 2021

Bibliographical note

Funding Information:
The study is funded by a grant from the Danish Health Authority social financing fund (Satspuljen), which covers the salaries for the primary investigators and the cryoneurolysis-related study costs. The RFA-related study cost is covered by the Department of Neurosurgery and Center for Experimental Neuroscience (CENSE).

Funding Information:
We are grateful for the advice from the members of the project Advisory Board on the study design and structure. Additionally, we want thank our project nurses, secretaries, physiotherapists and student volunteers, who play a vital role in the workflow and progression of the clinical trial. Lastly, we want to acknowledge colleagues from Silkeborg Spine center and Department of Orthopedic Surgery Aarhus University Hospital for their cooperation in referring potential participants in the inclusion stage.

Funding Information:
The study is funded by the Danish Health and Medicines Authority social financing fund “satspuljen” (7.3 mill. DKK).The grant covers the salaries of the primary investigators and the cryoneurolysis-related costs. The Department of Neurosurgery and Center for Experimental Neuroscience (CENSE) at Aarhus University Hospital covers all the RFA-related study costs.

Publisher Copyright:
© 2021, The Author(s).


  • Cryoanalgesia
  • Cryoneuroablation
  • Cryoneurolysis
  • Cryoneurolysis on lower-back pain
  • Low-back pain
  • Radiofrequency ablation


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