Cryoneurolysis for TKA - a Pilot Study

Total Knee Arthroplasty (TKA) is also known as a knee replacement. It is one of the most common orthopaedic (bone) surgeries performed and is usually very successful, but some people who have had a knee replacement feel pain that lasts for at least 3 months after surgery and thus continue to take pain control/ analgesic (opioids) medication. Opiates are medications like morphine.

Pain post-surgery can make it difficult to recover and return to daily activities. A better control of pain before the surgery, can help people feel less pain, recover faster, and use less opioids after surgery.

Cryoneurolysis means freezing the nerves that can cause pain. It uses very low temperatures in a specific body part (e.g., nerves to the knee) to freeze the pain nerves and therefore reduce the pain. When applied before the surgery it might help with postoperative pain after knee replacement.

This study will evaluate Iovera, a cryoneurolysis handheld device commercially available in Canada that delivers freezing cold to a target nerve by using nitrous oxide. Cryoneurolysis can relieve pain and symptoms associated with osteoarthritis of the knee for up to 90 days.

Patients undergoing total knee replacement (TKA) often experience a significant amount of pain during the immediate postoperative period, thus appropriate pain management before, during and after the surgery is a key component of patient satisfaction and better outcomes.

Opioids are the most commonly prescribed drugs to manage postoperative orthopaedic pain; however, their well-known side effects, such as nausea, vomiting and the potential high risk for dependence, can slow down recovery and lead to substance disorders.

Studies have reported, that more than 20% of patients receiving TKA experience persistent and unchanged pain post-surgery. Moreover, 15 to 25% of TKA patients continue the use of opioids at 3 months after surgery, 35% of patients report pain that interferes with their activities of daily living 4 months after surgery.

Adequate pain management before the surgery may prevent or reduce the rate of persistent pain and opioid usage after TKA. Cryoneurolysis is a minimally invasive procedure that uses a small probe to freeze \[at very low temperatures - below -20oC\] the target nerve. It can promote regeneration of the structure and function of the affected nerve. It has shown promising short and long-term results in a variety of acute and chronic pain conditions.

Retrospective studies revealed that preoperative cryoneurolysis might be efficacious in attenuating pain improving function and reducing opioid prescription 12 weeks after TKA. However, the studies are mostly retrospective, with small numbers of patients and not standardized knee specific outcomes.

This is a pilot randomized clinical trial to establish the feasibility of administering the study device (Iovera) to our target population as well as to test and refine the recruitment criteria, study design, patient acceptability, and operational strategies for use in a large definitive study.

Eligibility Criteria:
Inclusion Criteria:

* Male and female patients
* 18 to 80 years of age
* Patients with radiographic confirmation and clinical correlation for severe osteoarthritis diagnosis with an indication for total knee replacement
* Patients undergoing primary unilateral total knee replacement
* No previous unilateral knee injection (steroids/biologics) within 6 months of study
* The patient is able to read and understand English and provide informed consent to participation in the study

Exclusion Criteria:

* Pregnancy and breastfeeding
* Cryoglobulinemia
* Paroxysmal cold hemoglobinuria
* Cold urticaria
* Raynaud's disease
* Current Opioid use
* History of opiate, narcotic and alcohol abuse
* Revision total knee replacement surgery
* Open and/or infected wounds at or near the affected knee