Cryoneurolysis Improves Pain in Ankle Osteoarthritis

In patients with unilateral, symptomatic osteoarthritis (OA) of the ankle, the use of cryoneurolysis was associated with statistically significant improvements in ankle pain, physical function, and quality of life (QOL), according to study results published in Osteoarthritis and Cartilage Open.

Past studies have shown that cryoneurolysis is an effective treatment for the reduction of symptoms of knee OA and opioid use following knee arthroplasty. The researchers in the current study sought to evaluate clinically significant, long-term symptomatic relief of ankle OA with cryoneurolysis.

A single-center, single-arm, open-label clinical trial (ClinicalTrials.gov Identifier: NCT03567187) was conducted at the University of Kansas Medical Center (UKMC), located in Kansas City, Missouri, between August 13, 2018, and January 26, 2021. Participants were assigned to undergo cryoneurolysis of the superficial fibular nerve, the sural nerve, and/or the saphenous nerve or the deep fibular nerve with the use of ultrasound-guided cryoneurolysis.

All study participants met the following criteria:

1. They were older than age 18 years;
2. There was radiographic evidence of ankle OA (Kellgren-Lawrence Grade of at least 2);
3. Unilateral ankle pain was rated on a Numerical Rating Scale (NRS) as at least 5/10 on most days during the past month;
4. Foot and Ankle Outcome Score (FAOS) was less than 75 in at least 1 domain (on a scale of 0 to 100, with 100 representing the worst possible pain);
5. Body mass index was 50 kg/m² or lower;
6. They were ambulatory and able to comply with study procedures;
7. They had undergone at least 1 prior conservative treatment for OA (ie, physical therapy, analgesics, ankle brace); and
8. They were willing to abstain from the use of protocol-restricted medications during the study, as well as analgesics other than acetaminophen at 1 week prior to the beginning of the trial.

Study outcomes were evaluated at clinic visits (at 6 weeks, 12 weeks, and 24 weeks) and by telephone interview (at 3 weeks, 9 weeks, and 18 weeks). The primary study outcome was change in FAOS (pain subscale) at 12 weeks. Change in QOL (FAOS-QOL), activities of daily living (FAOS-ADL), pain-NRS, and physical performance were evaluated as well.

A total of 40 patients were enrolled in the trial. The mean participant age was 63.0±12.8 years; 50% of the patients were women. At 12 weeks posttherapy, statistically significant improvements were noted in FAOS-pain (20.8; P <.0001), ADL (18.1; P =.0003), QoL (19.9; P =.0003), and NRS-pain (-2.6; P <.0001). No significant difference was observed in the 40-meter fast-paced walking test at 12 weeks posttreatment (-1.2 seconds; P =.59). Similar findings were reported at the 6-week and 12-week visits.

One limitation of the study included the fact that an open-label design was used without a sham therapy, as this was the first study of cryoneurolysis for the treatment of ankle OA. The funding source chose to determine the magnitude of effect of the novel protocol used prior to initiation of a controlled trial.

The study authors concluded that the findings from this study support the use of cryoneurolysis as a safe, effective nonpharmacologic treatment for joint pain in patients with symptomatic ankle OA.

Disclosure: One of the study authors has declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the author’s disclosures. 

Reference  

Perry TA, Segal NA. An open-label, single-arm trial of cryoneurolysis for improvements in pain, Activities of Daily Living and Quality of Life in patients with symptomatic ankle osteoarthritis. Osteoarthr Cartil. Published online May 8, 2022. doi:10.1016/j.ocarto.2022.100272

This article originally appeared on Rheumatology Advisor