Cooling of the Knee After Total Knee Arthroplasty

Effects of the Cooling of the Knee After Total Knee Replacement: Does It Help Compared With a Standard Protocol?

This study investigates whether cooling the knee after total knee replacement surgery can reduce pain and improve early recovery. After surgery, patients are randomly assigned to one of three groups: cooling with a liquid cooling bandage, cooling with an ice pack, or standard postoperative care without cooling. Cooling begins 24 hours after surgery and continues for two weeks. Pain levels, use of pain medication, blood values, knee swelling, knee movement, and length of hospital stay are recorded. The goal is to determine whether postoperative knee cooling provides additional benefits compared with standard care.

Study Overview

• Status: Not yet recruiting
• Conditions: Osteoarthritis, Knee; Total Knee Replacement
• Intervention / Treatment: Other: Ice package cooling system; Other: Standard Postoperative Protocol Without Cooling; Device: Cool Down Liquid with Bandage ( CoolDown, CH)

Detailed Description

Postoperative pain, swelling, blood loss, and delayed functional recovery are common challenges after total knee arthroplasty (TKA). Cryotherapy has been proposed as a simple, non-invasive adjunct therapy to reduce these postoperative problems. However, published evidence is inconsistent because of differences in cooling devices, application duration, and study methodology.

This randomized controlled clinical trial aims to evaluate the clinical effectiveness of a standardized cooling protocol using a Cool Down liquid bandage compared with ice package cooling and a standard postoperative protocol without cooling in patients undergoing primary TKA. All patients receive the same implant design and standardized surgical and perioperative management.

Patients are randomized into three parallel groups: Cool Down liquid bandage cooling, ice package cooling, or no cooling. Cooling is initiated 24 hours postoperatively and continues for two weeks, three times daily. Passive knee motion using a continuous passive motion (CPM) machine is applied in all groups according to the same rehabilitation protocol.

The primary outcome is postoperative pain intensity measured by the Visual Analog Scale (VAS) at 48 hours after surgery. Secondary outcomes include opioid consumption expressed in morphine milligram equivalents (MME), changes in hemoglobin and erythrocyte levels, knee range of motion, knee swelling, and length of hospital stay.

The study is designed to clarify whether standardized postoperative knee cooling provides measurable clinical benefits and may help define evidence-based postoperative care pathways after total knee replacement.

• Study Type: Interventional
• Enrollment (Estimated): 99
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Oliver Dulic, MD, PhD; Phone Number: +381654404400; Email: oliver.dulic@mf.uns.ac.rs

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• • Adults undergoing primary total knee arthroplasty

  • Use of a primary knee prosthesis of identical design in all patients
  • Body mass index (BMI) < 35 kg/m²
  • Ability to understand the study protocol and comply with postoperative instructions
  • Absence of diagnosed mental disease

Exclusion Criteria:

• • Unregulated or poorly controlled diabetes mellitus

  • Rheumatoid arthritis or other inflammatory arthropathies
  • Presence of mental disease impairing cooperation or protocol adherence

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Ice Package Cooling System; Application of an ice package over the operated knee during in accordance with study protocol	Other: Ice package cooling system; Application of an ice package over the operated knee; Cooling initiated 24 hours after surgery; Cooling performed for 2 weeks postoperatively; Frequency: 3 times daily; Duration: 10 minutes per session; Cooling combined with passive knee motion using a continuous passive motion (CPM) machine according to the standard rehabilitation protocol
Other: Standard Postoperative Protocol Without Cooling; Standard postoperative care without cooling	Other: Standard Postoperative Protocol Without Cooling; Standard postoperative care without cooling; Passive knee motion using a CPM machine according to the same standard rehabilitation protocol
Experimental: Cool Down Liquid Cooling System; Application of Cool Down liquid bandage over the operated knee	Device: Cool Down Liquid with Bandage ( CoolDown, CH); The CoolDown Bandage is intended for postoperative local cooling and is capable of reducing skin and subcutaneous tissue temperature by approximately 7°C. Its proposed clinical benefits include reduction of postoperative pain, swelling, surgical-site bleeding, and opioid consumption. The bandage is designed to be applied directly over the surgical field for 2 hours per session, three times daily, allowing for prolonged and controlled cooling. This represents a significant advantage compared with conventional cryotherapy using ice packs, where the recommended application duration is typically limited to 10 minutes per session, three times daily, due to risks of cold-related tissue injury.This treatment should be started 24 hours after surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analog Scale	VAS (Visual Analog Scale) is a simple and widely used tool for measuring subjective pain intensity. It consists of a straight horizontal line, usually 10 cm long, with endpoints representing: 0 = no pain 10 = worst pain imaginable The patient marks a point on the line that best corresponds to their current pain level. The distance from the "no pain" end to the patient's mark is measured in centimeters or millimeters to quantify pain intensity.	From 24 hours to 14 days postoperatively (assessed at 24, 36, and 48 hours and at postoperative days 5, 7, and 14

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total opioid consumption	Total opioid consumption during hospitalization and up to 2 weeks postoperatively was quantified and standardized by conversion to morphine milligram equivalents (MME). MME represents a normalized measure of opioid exposure that accounts for differences in potency among various opioid agents. All administered and prescribed opioid doses were converted to their equianalgesic morphine dose using established opioid conversion tables, allowing direct comparison of cumulative opioid use across patients and treatment groupsAfter discharge, patients were instructed to prospectively record all analgesic medications consumed, including drug name, dosage, and frequency, in standardized medication diaries. Diary entries were reviewed during the 2-week postoperative follow-up visit and cross-checked with prescription records to ensure accuracy	from 48 hours to 2 weeks postoperatively
Changes in hemoglobin (Hgb) and erythrocyte (Er) levels	Serial measurements of hemoglobin (Hgb) and erythrocyte (Er) levels will be performed preoperatively and on postoperative days 1 and 3 to evaluate perioperative blood loss, hemodilution, and early hematologic recovery. The way how we desribe changes for this measure:Preoperative values (baseline) Represent the patient's starting hematologic status. Important for identifying preexisting anemia and estimating transfusion risk. Postoperative Day 1 (POD1) Typically shows the largest decrease in Hgb and Er. Reflects: Intraoperative blood loss Early postoperative bleeding Hemodilution due to IV fluids A sharp drop suggests significant perioperative blood loss. Postoperative Day 3 (POD3) Values often stabilize or partially recover. Reflects: Physiological compensation Mobilization of extravascular fluid Early erythropoietic response (though true RBC production takes longer) Continued decline may indicate ongoing bleeding or complications.	Assessed on postoperative day 1 and postoperative day 3
Active knee range of motion (ROM)	Active knee range of motion (ROM), defined as the maximal voluntary knee flexion and extension, was assessed using a handheld universal goniometer at discharge and at 2 weeks postoperatively, providing an objective measure of early postoperative functional outcomes.	Discharge day and 2 weeks postoperatively
Knee swelling measured by circumferential knee measurements	Postoperative knee swelling was evaluated by standardized circumferential measurements taken with a flexible tape measure at predefined anatomical landmarks at 48 hours, 7 days, and 2 weeks after surgery, allowing objective assessment of periarticular edema.	Assessed at 48 hours, 7 days, and 14 days postoperatively
Length of hospital stay	Hospital length of stay will be calculated as the total number of days from the day of surgery to the day of discharge and will be used as an indicator of early postoperative recovery, complication burden, and efficiency of perioperative care.	days from surgery to discharge

Collaborators and Investigators

• Sponsor: Clinical Center of Vojvodina

Publications and helpful links

General Publications

• Engelhard D, Hofer P, Annaheim S. Evaluation of the effect of cooling strategies on recovery after surgical intervention. BMJ open sport & exercise medicine. 2019 Jun 14;5(1).
• Krampe PT, Bendo AJ, Barros MI, Bertolini GR, Buzanello Azevedo MR. Cryotherapy in knee arthroplasty: systematic review and meta-analysis. Therapeutic hypothermia and temperature management. 2023 Jun 1;13(2):45-54.
• Yang L, Zhan YF, Zhai ZJ, Ruan H, Li HW. Mechanisms and parameters of cryotherapy intervention for early postoperative swelling following total knee arthroplasty: A scoping review. Journal of Experimental Orthopaedics. 2025 Jan;12(1):e70197.
• Wyatt PB, Nelson CT, Cyrus JW, Goldman AH, Patel NK. The role of cryotherapy after total knee arthroplasty: a systematic review. The Journal of Arthroplasty. 2023 May 1;38(5):950-6.
• Aggarwal A, Adie S, Harris IA, Naylor J. Cryotherapy following total knee replacement. Cochrane Database of Systematic Reviews. 2023(9).

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: January 29, 2026
• First Submitted That Met QC Criteria: February 13, 2026
• First Posted (Actual): February 18, 2026

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 13, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: knee osteoarthritis; total knee replacement; postoperative cooling
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee; Equipment and Supplies; Bandages
• Other Study ID Numbers: CCvojvodina

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All collected data
• IPD Sharing Time Frame: no limit
• IPD Sharing Access Criteria: no limit
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No