# Preoperative Cryogenic Neurolysis Trends Toward Reduced Severe Postoperative Pain in Patients Admitted to the Hospital After Total Knee Arthroplasty

## TL;DR

This study suggests that preoperative cryogenic neurolysis may help reduce severe postoperative pain after knee replacement surgery, though results were not statistically significant.

## Contribution

The study explores the potential of cryogenic neurolysis as a preoperative intervention to manage postoperative pain in total knee arthroplasty patients.

## Key findings

- Fewer patients in the cryogenic neurolysis group reported severe pain on postoperative day zero and one.
- No significant differences were found in opioid consumption or refills between the groups.
- Trends favored cryogenic neurolysis, but larger studies are needed to confirm its benefits.

## Abstract

Introduction

Cryogenic neurolysis is an emerging conservative intervention for knee pain. It involves the percutaneous application of low temperatures to peripheral nerves to produce a long-lasting nerve blockade. Although commonly used conservative treatments for knee osteoarthritis provide temporary relief and carry risks, cryogenic neurolysis may offer longer-term pain control with minimal complications. This study examined the trends of preoperative cryogenic neurolysis and its role in reducing postoperative pain and opioid consumption in patients undergoing total knee arthroplasty (TKA).

Methods

We conducted a retrospective observational study of all primary TKA patients treated by a single surgeon between February 21, 2023, and February 21, 2024. Patients were grouped based on whether they received cryogenic neurolysis within two weeks preoperatively. Outcomes included maximum visual analog scale (VAS) pain scores, morphine milligram equivalents (MME) administered on postoperative days zero and one, and opioid refills within six weeks. Statistical analyses included chi-square tests with effect sizes, two-sample t-tests, and Wilcoxon rank-sum tests.

Results

A total of 168 patients were included (92 cryogenic neurolysis; 76 controls). On postoperative day zero, 24 of 92 patients (26.1%) in the cryogenic neurolysis group and 24 of 76 patients (31.6%) in the control group reported severe pain (VAS ≥7), a non-significant difference (χ²(1, N = 168) = 0.62, p = 0.43, Cramer's V = 0.06). Among the subset of 128 overnight patients, 10 of 54 (18.5%) in the cryogenic neurolysis group and 19 of 74 (25.7%) in the control group reported severe pain on postoperative day one, also non-significant (χ²(1, N = 128) = 0.91, p = 0.34, Cramer's V = 0.08). No significant differences were found in inpatient MME consumption. Opioid refills were similar between groups, with 49 of 92 patients (53.3%) in the cryogenic neurolysis group and 43 of 76 patients (56.6%) in the control group receiving at least one refill (χ²(1, N = 168) = 0.18, p = 0.67, Cramer's V = 0.03).

Conclusions

Preoperative cryogenic neurolysis was not associated with statistically significant reductions in postoperative pain scores, inpatient MME usage, or opioid refills. However, a lower percentage of patients who received cryogenic neurolysis reported severe postoperative day zero and one pain, suggesting a possible early clinical benefit. Although trends favored the cryogenic neurolysis group, larger prospective studies are needed to better evaluate its role in multimodal pain management for TKA patients.