Correlation Between Intraoperative Tourniquet Use and Limb pH, Functional Measures and Patient-reported Outcomes After Ankle Fracture Surgery

Study Overview
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Brief Summary
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This study aims to 1) characterize skeletal muscle pH during/after tourniquet use and 2) investigate any relationship between intraoperative tourniquet use and postoperative functional measures and patient-reported outcomes.

Detailed Description
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Tourniquets are widely accepted as safe for up to two hours of continued use, despite known risks and a paucity of literature supporting this duration. Complications of tourniquets include tourniquet site pain, increased surgical site pain and swelling from reperfusion, neuropraxia, vascular injury, functional weakness, and decreased muscle endurance. Similar to compartment syndrome, tourniquets eliminate the tissue perfusion gradient necessary for oxygen, glucose, and lactic acid exchange. Lack of molecular exchange within the tissue is thought to result in tissue anoxia and acidosis, leading to cellular death of skeletal muscle and nerves. This study randomizes patients undergoing ankle fracture surgery to tourniquet or no-tourniquet arms and studies outcomes including continuous intramuscular pH during and after surgery, and patient-reported outcomes and functional measures up to 3 months postoperatively.

Official Title
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Correlation Between Intraoperative Tourniquet Use and Limb pH, Functional Measures and Patient-reported Outcomes After Ankle Fracture Surgery

Conditions
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Ankle Fractures, Ankle Fracture - Lateral Malleolus, Ankle Fracture, Bimalleolar, Ankle Fracture, Trimalleolar, Ankle Fracture - Medial Malleolus, Maisonneuve's Fracture, Syndesmotic Injuries, Fibula Fracture

Intervention / Treatment
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* Procedure: Tourniquet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients (18 years to 89 years) undergoing surgical ankle fracture fixation at OHSU Exclusion Criteria: sepsis other significant long bone or internal injuries (including ipsilateral limb injuries).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 89 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Tourniquet<br>This arm will have a tourniquet placed around the thigh inflated to 250mmHg for the duration of surgery (until splint placed) or 2 hours, whichever is shorter, during ankle fracture surgery. | Procedure: Tourniquet<br>* This arm will have a tourniquet placed about the thigh and inflated to 250mmHg for the duration of ankle fracture surgery or 2 hours, whichever is shorter.<br>|
| No Intervention: No Tourniquet<br>This arm will have a tourniquet placed around the thigh but NOT inflated for the duration of ankle fracture surgery. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient-Reported Outcomes Measurement Information System Physical Function Subscale | Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) subscale, a Patient Reported Outcome survey used widely in orthopaedic literature, will be obtained and reported in points | Collected preoperatively and at 3 week, 6 week and 12 week postoperatively | 
| Patient-Reported Outcomes Measurement Information System Pain Interference Subscale | Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference (PI) subscale, a Patient Reported Outcome survey used widely in orthopaedic literature, will be obtained and reported in points | Collected preoperatively and at 3 week, 6 week and 12 week postoperatively | 
| Foot and Ankle Ability Measure | Foot and Ankle Ability Measure, a Patient Reported Outcome survey used widely in orthopaedic Foot and Ankle literature, will be obtained and reported in points | Collected preoperatively and at 3 week, 6 week and 12 week postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Score | Patients will score their pain on a Visual Analog pain scale (VAS) (0-10) | Assessed preoperatively and at 2 hours and 3, 6 and 12 weeks postoperatively | 
| Malleolar circumference | bilateral malleolar circumference in cm will be measured by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Calf girth | bilateral calf girth in cm will be measured by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Mobility | Mobility, via timed up and go test in seconds, will be measured by blinded physical therapists. Patients will be seated in a chair and the time to rise, walk 10 feet, turn, walk back to the chair and sit down will be recorded in seconds. | Collected at 6 weeks and 12 weeks postoperatively | 
| Ankle range of motion | ankle range of motion (flexion, extension, inversion, eversion) will be measured in degrees with goniometer by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Fatigability | Utilizing a biodex machine, fatigability or total work in foot pounds, will be measured by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Proximal and distal lower extremity strength | proximal and distal lower extremity strength, via handheld dynamometer, in lb will be measured by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Single-limb stance time | Single-limb stance time (seconds) will be measured by blinded physical therapists | Collected at 6 weeks and 12 weeks postoperatively | 
| Y-balance test scores | Y-balance test composite score (%) will be measured by blinded physical therapists. For this test, the length of the extremity is measured and the patient reaches the extremity for the longest distance in three planes (anterior, posteriomedial, posterolateral) and the greatest distances achieved are recorded. The score is obtained by the sum of the greatest distances reached in each plane divided by 3x the limb length. | Collected at 6 weeks and 12 weeks postoperatively | 
| Limb pH | a VersaFlex® pH catheter from the Covidien pH monitoring kit will be placed in the anterior compartment of the operative leg via small incision and the Digitrapper® Recorder will measure and record continuous intramuscular pH | Recording will start immediately after placement of the probe and will continue intraoperatively and for 2 hours postoperatively |