Myonecrosis: A Rare Complication of Cryoneurolysis

Considered a safe and effective procedure, cryoneurolysis has been used to provide pain relief for chronic joint pain for decades. The procedure is similar to common ultrasound-guided percutaneous procedures. Although the literature is limited on the efficacy and safety of cryoneurolysis, there is a consensus that the use of cryoneurolysis is effective, with a risk profile similar to that of other percutaneous procedures.

We are reporting the case of a 74-year-old male who underwent cryoneurolysis for chronic right knee pain. Initially, the patient had complete symptomatic improvement, but subsequently developed rigors and right knee swelling, prompting him to seek emergency medical care. Computed tomography angiography was significant for myonecrosis and phlegmon with early abscess formation. The patient continued to improve symptomatically with i.v. antibiotics. He was discharged home on hospital day 8 with a peripherally inserted central catheter. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cryoneurolysis will likely continue to gain popularity as an option for pain management in osteoarthritis and other degenerative joint diseases. It is essential for physicians to be alert to the possibility of severe, albeit rare, complications of a seemingly safe procedure, given the potential to impact a patient's morbidity and quality of life drastically.