Summary

Adding preoperative percutaneous cryoneurolysis to our previous analgesia regimen was shown to be superior to adductor canal blockade in decreasing opioid requirements and hospital length of stay while having fewer complications.

Abstract

Introduction

Post-operative pain control following total knee arthroplasty (TKA) remains a relevant topic without a single superior solution. Use of oral opioid medications postoperatively is common, but over-utilization of opioids is well reported and limiting their use has become an emphasis. Additionally, pain after surgery has been shown to be one of the most common reasons for unexpected hospital stays following TKA. Previous modalities included both single shot and continuous peripheral nerve blockade which have had well documented drawbacks and complications. Percutaneous cryoneurolysis (PCN) of the infrapatellar branch of the saphenous nerve and the anterior femoral cutaneous nerve is a relatively novel technique that has shown promise in limiting postoperative opioid use and shortening hospital length of stay (LOS) following primary TKA.

Methods

This was a retrospective cohort study of 157 consecutive patients who received primary TKA by a single surgeon at a single institution. Patients were separated into two cohorts based on whether or not they received preoperative PCN within 90 days of their surgery. All patients received periarticular intraoperative local anesthetic. Demographic, complication and prescription data was obtained from patients’ electronic medical records. Exclusion criteria included chronic pain, neuropathy diagnosis, and requirement of opioids within 3 months of surgery for another diagnosis.

Results

131 patients (73 with PCN and 58 without PCN) met final inclusion/exclusion criteria. PCN was completed 15.6 ± 1.2 days prior to surgery and all patients received the treatment within 90 days of the surgical date. There was no significant difference in demographic data between the two groups. The PCN group received 138.0 morphine milligram equivalents (MME) fewer in prescribed oral opioids than the group who did not receive PCN (p=.038). The PCN group also had .70 fewer opioid refills (p=.004) and had a .46 day shorter LOS (p=.002). There was no significant difference in overall complication rate or related emergency department visits between the groups. Forty-four patients received either single shot or continuous adductor canal blockade (ACB) in an ACB subgroup. Forty-one received continuous catheters and 3 received single shot blockades. No patients received both ACB and PCN. The PCN group received 186 fewer MME (p=.010) and had a .33 day shorter LOS (p=.024). There was an 8% decrease in the rate of postoperative manipulations under anesthesia for stiffness in the PCN group which approached statistical significance (p=.066). 13/44 (30%) patients in the ACB group reported catheter leaking or unintended motor blockade. There were no complications reported relating to the PCN procedure.

Discussion

Patients in the PCN group received fewer opioids and had shorter LOS than the control group. This is the first study of its kind that directly compared PCN with ACB. When compared specifically to ACB, PCN continued to demonstrate less overall opioid use and shorter LOS without any peripheral nerve blockade related complications which were common. The fewer manipulations under anesthesia required in the PCN group may indicate increased tolerance towards early physical therapy.

Conclusion

Preoperative PCN is a safe and effective adjunct to post operative pain control following primary TKA.