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Preoperative CT-Guided Cryoneurolysis of the Genicular Nerves Before Total Knee Arthroplasty: Study Protocol for a
Vasileios Balomenos1, Ornella Moschovaki-Zeiger2, Panagiotis Koulouvaris3
1Department of Diagnostic & Interventional Radiology, Medical School, Attikon" University General Hospital, National & Kapodistrian University of Athens, Athens, Greece. balomenosv@gmail.com.
Purpose:
Pain control and early mobility remain primary challenges after Total Knee Arthroplasty (TKA). This study will evaluate whether pre-TKA CT-guided cryoneurolysis of the genicular nerves improves postoperative pain, mobility, and quality of life in patients with knee osteoarthritis.
Materials And Methods:
One hundred patients undergoing unilateral TKA will be randomized 1:1 in this prospective, open-label trial. Intervention patients will receive CT-guided cryoneurolysis of three genicular nerves (superior medial, superior lateral, and inferior medial) 24-72h before surgery; controls will undergo TKA alone. Chronic opioid users and patients unable to self-assess are excluded. Perioperative analgesia and rehabilitation will be standardized. Patients will be assessed preoperatively and at 1, 3, 6, and 12 months using the Brief Pain Inventory (BPI), Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Quality of Life Index (QLI). The primary endpoint is the BPI Pain Interference Scale at 3 months; secondary endpoints include KOOS, WOMAC, and QLI scores, opioid consumption (morphine milligram equivalents), time to mobilization, and length of stay. Safety endpoints comprise adverse events of either procedure, graded by the modified CIRSE classification.
Expected Outcomes:
One hundred patients provide >80% power to detect the minimal clinically important difference of 1.5 points on the BPI Pain Interference Scale. We hypothesize superior pain relief and function with cryoneurolysis.
Conclusion:
This protocol evaluates a long-acting, opioid-sparing analgesic approach using interventional radiology techniques. If superiority is demonstrated, preoperative cryoneurolysis could become a standard "pre-habilitation" (preoperative functional optimization) tool after TKA.
Trial Registration:
This study protocol has been registered in ClinicalTrials.gov (Identifier: NCT07425457) and follows the SPIRIT guidelines for interventional trials and adheres to the Declaration of Helsinki. The study has been approved by the Ethics Committee and Institutional Review Board of the National and Kapodistrian University of Athens (Approval ID: A9, 10/09/2025). Informed consent will be obtained from every individual participant included in the study.
Clinicaltrials:
gov, CRYO-TKA Trial, NCT07425457. Registered on 20/02/2026 LEVEL OF EVIDENCE: Not applicable (study protocol).
