Knee ArthroplastyNCT07747116
Knee Positioning After Total Knee Replacement
A study testing Knee Flexion in people with Knee Arthroplasty, run by Icahn School of Medicine at Mount Sinai at 1 site in United States.
Trial summary
Many total knee replacements are performed each year, but there is no clear recommendation regarding knee positioning following this surgery. While the surgical knee is usually positioned in a straight position immediately after surgery, there may be benefits of positioning it in a partially bent position. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Knee Arthroplasty
- What is being tested?
- Knee Flexion
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- Oct 2026to Feb 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Males and females; Age >18 years
- Scheduled for elective primary unilateral total knee arthroplasty
- The planned arthroplasty is secondary to physician-confirmed diagnosis of knee osteoarthritis
- English- or Spanish-speaking
Who cannot join
- Patients with a history of chronic opioid use or chronic pain disorders
- Patients with a history of bleeding disorders/coagulopathy
- Patients receiving a total knee replacement secondary to trauma, avascular necrosis, tumor, or Charcot arthropathy
- Patients scheduled to undergo multiple procedures simultaneously
- Patients with cognitive impairment or inability to consent independently
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Mount Sinai Health System
New York, New York, 10029
Brocha Stern, (212) 659-9650, brocha.stern@mountsinai.org
About this study
Official title: The Effects of Postoperative Positioning in Knee Flexion Versus Usual Care After Total Knee Arthroplasty: A Randomized Controlled Trial
Many total knee replacements are performed each year, but there is no clear recommendation regarding knee positioning following this surgery. While the surgical knee is usually positioned in a straight position immediately after surgery, there may be benefits of positioning it in a partially bent position. A trial will compare the outcomes of two groups of patients: a) those whose knees are positioned in a partially bent position for a few hours after surgery and b) those who receive usual care where the knee is most likely positioned in a straight position. The investigators are looking to see whether knee motion and pain differ for patients in the two groups.
Read the detailed description
This parallel two-arm randomized controlled trial will compare outcomes for knee flexion versus usual care in the immediate postoperative period after total knee arthroplasty. Patients who are scheduled for elective primary unilateral total knee arthroplasty will be recruited from an academic health system, screened for inclusion/exclusion criteria, and enrolled. The experimental group will have their surgical knee positioned in approximately 60° of flexion for 2-4 hours after surgery. The control group will receive usual care, where the knee will generally be positioned in extension. Other than the study intervention, both groups will receive standard perioperative, intraoperative, and postoperative care as determined by their treating clinical team. The co-primary endpoints are 6-week knee passive total arc of motion and 7-day maximum pain intensity. Secondary outcomes will be assessed throughout the 12 months after surgery and will include knee motion and pain intensity at other time points; oral opioid consumption; patient-reported questionnaires of knee health, quality of life, and satisfaction; healthcare utilization; and complications. Adverse events will also be monitored for the 12 months after surgery. Outcomes will be assessed via phone or electronic surveys; routine care visits at 2.5 weeks, 6 weeks, 3 months, 6 months, and 12 months after surgery; and chart review.
- Conditions
- Knee Arthroplasty
- Being tested
- Knee Flexion, Standard Care
- Keywords
- Knee Flexion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Knee FlexionOther
Participants will receive knee flexion postoperatively following primary total knee arthroplasty. The surgical knee will positioned at approximately 60° flexion using an abduction pillow as a jig underneath the knee during the immediate postoperative recovery period. Positioning will occur following surgery while the participant is still in the operating room. This is a soft construct and a noninvasive intervention. A goniometer will be used to approximate 60° of flexion as closely as possible. It is expected that the knee will be positioned for 2-4 postoperative hours until a physical therapist comes to mobilize the patient. However, the duration may vary because of the pragmatic context. There is no minimum or maximum positioning time that would make the intervention duration ineligible.
Standard CareProcedure or surgery
Participants in this arm will receive usual care. No specific attention will be placed to knee positioning in the immediate period after surgery. However, the current usual practice in the health system is that the knee is positioned in extension.
| Study group | Role | What they receive |
|---|---|---|
| Knee Flexion | Experimental | Participants in this arm will receive the knee flexion intervention. Receives: Other: Knee Flexion |
| Usual Care | Active comparator | Participants in this arm will receive usual care. No specific attention will be placed to knee positioning in the immediate period after surgery. However, the current usual practice in the health system is that the knee is positioned in extension. Receives: Procedure: Standard Care |
What is being measured
The primary outcome is the main question the study is designed to answer.
Knee Passive Total Arc of Motion
Passive total arc of motion will be evaluated through goniometric assessment of maximal passive knee flexion and passive knee extension. Both measures will be recorded, but a single endpoint will be derived by subtracting available extension from available flexion.
Measured: At 6 weeks after surgery
Maximum Pain Intensity
Pain intensity will be evaluated via the patient-reported Numeric Rating Scale (NRS) for pain. The rating is from 0 to 10, with a higher score indicating worse pain. The worst (i.e., maximum) pain intensity will be used.
Measured: At 7 days after surgery
Secondary outcomes (19)
Knee Passive Total Arc of Motion
Passive total arc of motion will be evaluated through goniometric assessment of maximal passive knee flexion and passive knee extension. Both measures will be recorded, but a single endpoint will be derived by subtracting available extension from available flexion.
Measured: At 2.5 weeks, 3 months, 6 months, and 12 months after surgery
Maximum Pain Intensity
Pain intensity will be evaluated via the patient-reported Numeric Rating Scale (NRS) for pain. The rating is from 0 to 10, with a higher score indicating worse pain. The worst (i.e., maximum) pain intensity will be used.
Measured: At 0 days, 1 day, 2 days, 3 days, 10 days, 14 days, 2.5 weeks, 6 weeks, 3 months, 6 months, and 12 months after surgery
Total Opioid Consumption
Consumption of opioids standardized in oral morphine milligram equivalents based on medical records for in-hospital administration, prescriptions, and patient report for at-home consumption. Consumption will be summed across days, with higher numbers indicating greater opioid consumption.
Measured: Postoperative days 0 through 14
Knee Injury and Osteoarthritis Outcome Score for Joint Replacement
The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) is a patient-reported measure of knee health (i.e., pain and function). Scores range from 0 to 100, with higher scores indicating better health.
Measured: At 6 weeks, 3 months, 6 months, and 12 months after surgery
Veterans RAND 12-item Health Survey
The Veterans RAND 12-item Health Survey (VR-12) is a patient-reported measure of global physical and mental health. It provides a physical component summary score and a mental component summary score. These are T-scores with a mean of 50, and higher scores indicate better health.
Measured: At 6 weeks, 3 months, 6 months, and 12 months after surgery
Goodman Satisfaction Score
The Goodman Satisfaction Score assesses patient satisfaction with total hip or knee arthroplasty outcomes. Scores range from 0 to 100, with higher scores indicating greater satisfaction.
Measured: 12 months after surgery
Length of Hospital Stay
Number of days the patient stays in the hospital after the index surgery. This information will be extracted from the medical record.
Measured: Through hospital discharge, average of 1 day, up to 30 days after surgery
Percentage of Participants with an Emergency Department Visit
Percentage of participants with an all-cause emergency department visit after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 7 days, 30 days, and 90 days after surgery
Percentage of Participants with a Hospital Readmission
Percentage of participants with an all-cause hospital readmission after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with Deep Vein Thrombosis
Percentage of participants who have deep vein thrombosis after surgery.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Pulmonary Embolism
Percentage of participants who have a pulmonary embolism after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Venous Thromboembolism
Percentage of participants who have a venous thromboembolism after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Coronary Event
Percentage of participants who have a myocardial infarction or other coronary event after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Stroke
Percentage of participants who have a stroke after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Blood Transfusion
Percentage of participants who receive a blood transfusion after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days after surgery
Percentage of Participants with a Wound Dehiscence
Percentage of participants who have a wound dehiscence after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Mechanical Complication
Percentage of participants who have a mechanical complication after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 30 days and 90 days after surgery
Percentage of Participants with a Manipulation under Anesthesia
Percentage of participants who undergo a manipulation under anesthesia after surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 12 months after surgery
Percentage of Participants with a Knee Revision Surgery
Percentage of participants who undergo a knee revision surgery after the index surgery. This information will be extracted from the medical record, with supplementation by participant queries during the postoperative visit after the respective timepoint.
Measured: Within 12 months after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2026
- Study startOct 2026 (estimated)
- Primary completionFeb 2028 (estimated)
- Study completionFeb 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Knee ArthroplastyStudies of the same condition, open and under way.
- More trials run by Icahn School of Medicine at Mount SinaiThe sponsor's other registered studies.
- 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
- Single blind
- Who is masked
- Care provider
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Icahn School of Medicine at Mount Sinai
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Brett Hayden, Icahn School of Medicine at Mount Sinai
- Investigators
- Brett Hayden, MD, Principal investigator, Icahn School of Medicine at Mount Sinai
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07747116
- Sponsor's protocol ID
- Study 26-00680
- Status last verified
- Sep 2026
- First submitted
- 30 Jul 2026
- Last updated
- 7 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: No individual participant data is planned to be shared with other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Postoperative Positioning in Knee Flexion Versus Usual Care After Total Knee Arthroplasty: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07747116
- Acronym / sponsor ID
- Study 26-00680
- Conditions
- Knee Arthroplasty
- Keywords
- Knee Flexion
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Icahn School of Medicine at Mount SinaiUniversity, hospital or other
- Study start
- Oct 2026 (estimated)
- Primary completion
- Feb 2028 (estimated)
- Study completion
- Feb 2029 (estimated)
- First posted
- 5 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Many total knee replacements are performed each year, but there is no clear recommendation regarding knee positioning following this surgery. While the surgical knee is usually positioned in a straight position immediately after surgery, there may be benefits of positioning it in a partially bent position. A trial will compare the outcomes of two groups of patients: a) those whose knees are positioned in a partially bent position for a few hours after surgery and b) those who receive usual care where the knee is most likely positioned in a straight position. The investigators are looking to see whether knee motion and pain differ for patients in the two groups.
Detailed description
This parallel two-arm randomized controlled trial will compare outcomes for knee flexion versus usual care in the immediate postoperative period after total knee arthroplasty. Patients who are scheduled for elective primary unilateral total knee arthroplasty will be recruited from an academic health system, screened for inclusion/exclusion criteria, and enrolled. The experimental group will have their surgical knee positioned in approximately 60° of flexion for 2-4 hours after surgery. The control group will receive usual care, where the knee will generally be positioned in extension. Other than the study intervention, both groups will receive standard perioperative, intraoperative, and postoperative care as determined by their treating clinical team. The co-primary endpoints are 6-week knee passive total arc of motion and 7-day maximum pain intensity. Secondary outcomes will be assessed throughout the 12 months after surgery and will include knee motion and pain intensity at other time points; oral opioid consumption; patient-reported questionnaires of knee health, quality of life, and satisfaction; healthcare utilization; and complications. Adverse events will also be monitored for the 12 months after surgery. Outcomes will be assessed via phone or electronic surveys; routine care visits at 2.5 weeks, 6 weeks, 3 months, 6 months, and 12 months after surgery; and chart review.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (care provider)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Knee Flexion | Experimental | Other: Knee FlexionParticipants in this arm will receive the knee flexion intervention. |
| Usual Care | Active comparator | Procedure: Standard CareParticipants in this arm will receive usual care. No specific attention will be placed to knee positioning in the immediate period after surgery. However, the current usual practice in the health system is that the knee is positioned in extension. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Males and females; Age >18 years
- Scheduled for elective primary unilateral total knee arthroplasty
- The planned arthroplasty is secondary to physician-confirmed diagnosis of knee osteoarthritis
Key exclusion criteria (5 listed)
- Patients with a history of chronic opioid use or chronic pain disorders
- Patients with a history of bleeding disorders/coagulopathy
- Patients receiving a total knee replacement secondary to trauma, avascular necrosis, tumor, or Charcot arthropathy
- Patients scheduled to undergo multiple procedures simultaneously
- Patients with cognitive impairment or inability to consent independently
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Knee FlexionParticipants will receive knee flexion postoperatively following primary total knee arthroplasty. The surgical knee will positioned at approximately 60° flexion using an abduction pillow as a jig underneath the knee during the immediate postoperative recovery period. Positioning will occur following surgery while the participant is still in the operating room. This is a soft construct and a noninvasive intervention. A goniometer will be used to approximate 60° of flexion as closely as possible. It is expected that the knee will be positioned for 2-4 postoperative hours until a physical therapist comes to mobilize the patient. However, the duration may vary because of the pragmatic context. There is no minimum or maximum positioning time that would make the intervention duration ineligible. | Other | Knee Flexion |
| Standard CareParticipants in this arm will receive usual care. No specific attention will be placed to knee positioning in the immediate period after surgery. However, the current usual practice in the health system is that the knee is positioned in extension. | Procedure or surgery | Usual Care |
Primary outcome
Knee Passive Total Arc of Motion
Time frame: At 6 weeks after surgery
Passive total arc of motion will be evaluated through goniometric assessment of maximal passive knee flexion and passive knee extension. Both measures will be recorded, but a single endpoint will be derived by subtracting available extension from available flexion.
Maximum Pain Intensity
Time frame: At 7 days after surgery
Pain intensity will be evaluated via the patient-reported Numeric Rating Scale (NRS) for pain. The rating is from 0 to 10, with a higher score indicating worse pain. The worst (i.e., maximum) pain intensity will be used.
19 secondary outcomes
Knee Passive Total Arc of Motion
Time frame: At 2.5 weeks, 3 months, 6 months, and 12 months after surgery
Maximum Pain Intensity
Time frame: At 0 days, 1 day, 2 days, 3 days, 10 days, 14 days, 2.5 weeks, 6 weeks, 3 months, 6 months, and 12 months after surgery
Total Opioid Consumption
Time frame: Postoperative days 0 through 14
Knee Injury and Osteoarthritis Outcome Score for Joint Replacement
Time frame: At 6 weeks, 3 months, 6 months, and 12 months after surgery
Veterans RAND 12-item Health Survey
Time frame: At 6 weeks, 3 months, 6 months, and 12 months after surgery
Goodman Satisfaction Score
Time frame: 12 months after surgery
Length of Hospital Stay
Time frame: Through hospital discharge, average of 1 day, up to 30 days after surgery
Percentage of Participants with an Emergency Department Visit
Time frame: Within 7 days, 30 days, and 90 days after surgery
Percentage of Participants with a Hospital Readmission
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with Deep Vein Thrombosis
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Pulmonary Embolism
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Venous Thromboembolism
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Coronary Event
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Stroke
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Blood Transfusion
Time frame: Within 30 days after surgery
Percentage of Participants with a Wound Dehiscence
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Mechanical Complication
Time frame: Within 30 days and 90 days after surgery
Percentage of Participants with a Manipulation under Anesthesia
Time frame: Within 12 months after surgery
Percentage of Participants with a Knee Revision Surgery
Time frame: Within 12 months after surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Oct 2026.
- Individual participant dataSharing planned: No. No individual participant data is planned to be shared with other researchers.
Related trials for Knee Arthroplasty
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Opioid Reduction and Enhanced Recovery in Orthopaedic Surgery (OREOS)-Knee
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Evaluation of PLG0206 in Prevention of Recurrent Infection in Patients Undergoing Debridement, Antibiotics, and Implant Retention (DAIR) for Treatment of a Periprosthetic Joint Infection (PJI) Following Knee Arthroplasty
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Not yet recruitingObservational study
Agreement Between Patient-Reported Pain, Observer-Rated Pain Behavior, and Analgesic Request After Total Knee Arthroplasty
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Brett Hayden, MD principal investigator
Icahn School of Medicine at Mount Sinai
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Knee Flexion in people with Knee Arthroplasty, run by Icahn School of Medicine at Mount Sinai at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 7 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Brocha Stern (212-659-9650, brocha.stern@mountsinai.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Knee Passive Total Arc of Motion (time frame: At 6 weeks after surgery). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Oct 2026.