Osteoarthritis, KneeNCT07416721
Cooling of the Knee After Total Knee Arthroplasty
A study testing Cool Down Liquid with Bandage ( CoolDown, CH), Ice package cooling system and Standard Postoperative Protocol Without Cooling in people with Osteoarthritis, Knee and Total Knee Replacement, run by Clinical Center of Vojvodina at 1 site in Serbia.
Trial summary
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. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Osteoarthritis, Knee, Total Knee Replacement
- What is being tested?
- Cool Down Liquid with Bandage ( CoolDown, CH), Ice package cooling system and Standard Postoperative Protocol Without Cooling
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 99 participants
- Where
- 1 siteSerbia
- Study dates
- 1 Mar 2026to 1 Oct 2026
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- • 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
Who cannot join
- • Unregulated or poorly controlled diabetes mellitus
- Rheumatoid arthritis or other inflammatory arthropathies
- Presence of mental disease impairing cooperation or protocol adherence
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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.
Read the 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.
- Conditions
- Osteoarthritis, Knee, Total Knee Replacement
- Being tested
- Cool Down Liquid with Bandage ( CoolDown, CH), Ice package cooling system, Standard Postoperative Protocol Without Cooling
- Keywords
- knee osteoarthritis, postoperative cooling, total knee replacement
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cool Down Liquid with Bandage ( CoolDown, CH)Device
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.
Ice package cooling systemOther
- 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
Standard Postoperative Protocol Without CoolingOther
- Standard postoperative care without cooling
- Passive knee motion using a CPM machine according to the same standard rehabilitation protocol
| Study group | Role | What they receive |
|---|---|---|
| Ice Package Cooling System | Active comparator | Application of an ice package over the operated knee during in accordance with study protocol Receives: Other: Ice package cooling system |
| Standard Postoperative Protocol Without Cooling | Other | Standard postoperative care without cooling Receives: Other: Standard Postoperative Protocol Without Cooling |
| Cool Down Liquid Cooling System | Experimental | Application of Cool Down liquid bandage over the operated knee Receives: Device: Cool Down Liquid with Bandage ( CoolDown, CH) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: From 24 hours to 14 days postoperatively (assessed at 24, 36, and 48 hours and at postoperative days 5, 7, and 14
Secondary outcomes (5)
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
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: days from surgery to discharge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Feb 2026
- Study start1 Mar 2026
- Primary completion1 Oct 2026
- Study completion1 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Osteoarthritis, KneeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 99 participants (actual)
Sponsor and investigators
- Lead sponsor
- Clinical Center of Vojvodina
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, dr Oliver Dulic MD,PhD, Clinical Center of Vojvodina
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07416721
- Sponsor's protocol ID
- CCvojvodina
- Status last verified
- Feb 2026
- First submitted
- 29 Jan 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All collected data
Publications
Engelhard D, Hofer P, Annaheim S. Evaluation of the effect of cooling strategies on recovery after surgical intervention. BMJ Open Sport Exerc Med. 2019 Jun 14;5(1):e000527. doi: 10.1136/bmjsem-2019-000527. eCollection 2019.
PubMed 31275604Krampe PT, Bendo AJP, Barros MIG, Bertolini GRF, Buzanello Azevedo MR. Cryotherapy in Knee Arthroplasty: Systematic Review and Meta-Analysis. Ther Hypothermia Temp Manag. 2023 Jun;13(2):45-54. doi: 10.1089/ther.2022.0043. Epub 2022 Dec 5.
PubMed 36472555Yang 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. J Exp Orthop. 2025 Mar 7;12(1):e70197. doi: 10.1002/jeo2.70197. eCollection 2025 Jan.
PubMed 40059958Wyatt PB, Nelson CT, Cyrus JW, Goldman AH, Patel NK. The Role of Cryotherapy After Total Knee Arthroplasty: A Systematic Review. J Arthroplasty. 2023 May;38(5):950-956. doi: 10.1016/j.arth.2022.12.004. Epub 2022 Dec 8.
PubMed 36496048Aggarwal A, Adie S, Harris IA, Naylor J. Cryotherapy following total knee replacement. Cochrane Database Syst Rev. 2023 Sep 14;9(9):CD007911. doi: 10.1002/14651858.CD007911.pub3.
PubMed 37706609