The Effect of Ischemic Preconditioning on Postoperative Pain After Total Knee Arthroplasty, a Randomized, Controlled Trial

Study Overview
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Brief Summary
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The application of a tourniquet for 5 minutes and subsequent reperfusion before actual inflation of the tourniquet for total knee arthroplasty (ischemic preconditioning) decreases the level of local inflammation and therefore postoperative pain in response to reperfusion of the ischemic extremity.

Detailed Description
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During knee surgery your surgeon routinely uses a device called a tourniquet that allows us to temporarily cut of blood supply to the site of surgery. This helps to reduce blood loss and improves operating conditions. When allowing blood back into your leg at the end of the procedure, debris (bone, fat, tissue breakdown products and cement from the surgery) gets washed out and gains access to the rest of your body. In the vast majority of cases this event bares no major clinical consequences, but can rarely result in signs of inflammation of various body systems. Patients with evidence of impaired organ system function such as pre-existing lung and heart disease may be more vulnerable. Previous studies suggest that cutting off the blood supply for a short period of time just before a prolonged episode, could lead to a decrease in the extent of tissue breakdown products in this extremity and may thus be associated with a decrease in the inflammation of other organ systems. We propose to study this theory in knee surgery patients by looking at levels of markers of inflammation present in the blood before and after surgery.

Official Title
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The Effect of Ischemic Preconditioning on Postoperative Pain After Total Knee Arthroplasty, a Randomized, Controlled Trial

Conditions
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Total Knee Arthroplasty, Ischemic Preconditioning, Postoperative Pain

Intervention / Treatment
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* Procedure: Ischemic Preconditioning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients undergoing primary total knee arthroplasty Exclusion Criteria: Patients who chronically use narcotics (<1 month). Patients with contraindications (severe peripheral vascular disease, presence of femoral-popliteal bypass grafts, etc.) or no plan for tourniquet use as determined by the clinical care team. Patients who are on corticosteroids prior to their surgery

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Ishcemic Preconditioning<br>In the study group, the patients' operative limb will be preconditioned by inflating the tourniquet for 5 minutes, followed by deflation and a 5-minute reperfusion period. Subsequently, the tourniquet will be inflated for the entire length of the operation (before skin incision to after insertion of the final components). | Procedure: Ischemic Preconditioning<br>* In the study group, the patients' operative limb will be preconditioned by inflating the tourniquet for 5 minutes, followed by deflation and a 5-minute reperfusion period. Subsequently, the tourniquet will be inflated for the entire length of the operation (before skin incision to after insertion of the final components). In the control group, the tourniquet will be used for the entire length of the operation without a preconditioning phase.<br>|
| No Intervention: Control<br>In the control group, the tourniquet will be used for the entire length of the operation without a preconditioning phase. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain at rest and exercise as assessed by VAS scores on 6h, 24h, and 48h after surgery |  | Up to 48hrs after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall epidural volume and oioid consumption over 48h |  | Up to 48hrs after surgery | 
| Muscle oxygenation over calf as measured by non-invasive infrared spectroscopy pre-surgery, 6h, 24h, and 48h after surgery |  | Up to 48 hrs after surgery | 
| Levels of leukocytes and tumor necrosis factor-alpha (TNF) and Interleukin 6 (IL6) in drainage fluid at 24hr postoperatively |  | 24 hours postoperatively | 
| Periarticular circumference of the knee at 6h, 24h, and 48h | Periarticular circumference of the knee as compared to contralateral side as curde marker of swelling at 6h, 24, and 48h postoperatively | Up to 48h | 
| Hospital length of stay |  | Up to discharge date | 
| Physical theraphy milestone | Ambulation of 40ft, independent transfer, and range of motion of operative leg | Up to discharge date |