Knee Positioning After Total Knee Replacement

Official title

The Effects of Postoperative Positioning in Knee Flexion Versus Usual Care After Total Knee Arthroplasty: A Randomized Controlled Trial

Overview

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.

Interventions

• Other Knee Flexion
  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.
• Procedure Standard Care
  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.

Primary outcome measures

• Knee Passive Total Arc of Motion [Time frame: At 6 weeks after surgery]
• Maximum Pain Intensity [Time frame: At 7 days after surgery]

Secondary outcome measures (12)

• 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]

Eligibility criteria

Inclusion criteria

• 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

Exclusion criteria

• 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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

United States · 1 center

• Mount Sinai Health System — New York

Identifiers

NCT: NCT07747116 · Study 26-00680

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗