Total Knee Arthroplasty Utilizing Adductor Canal Block: Effect on Quadriceps Sparing

Study Overview
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Brief Summary
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The purpose of this study is to investigate whether there is quantitative motor-sparing of the quadriceps muscles following adductor canal nerve block versus femoral nerve block. Patients will be randomly placed into one of three treatment groups: 1) Femoral nerve block, 2) Adductor canal nerve block - low volume, or 3) Adductor canal nerve block - high volume. Quadriceps function will be assessed in the operating room using a skin patch and electrical stimulation. Follow up visits with the patients will continue over the course of 2 days during patient's stay at the hospital. A total of 60 patients will be enrolled for the study.

Official Title
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Postoperative Pain Management Following Total Knee Arthroplasty Utilizing Adductor Canal Block: Effects on Pain Management and Quadriceps Sparing

Conditions
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Osteoarthritis (Knee)

Intervention / Treatment
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* Procedure: High Volume Adductor Canal Block
* Procedure: Low Volume Adductor Canal Block
* Procedure: Femoral Nerve Block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients undergoing primary unilateral total knee arthroplasty Planned use of combined spinal epidural (CSE) anesthesia Ability to follow study protocol Exclusion Criteria: Contraindication to a spinal or epidural anesthetic Chronic opioid use (defined as daily or almost daily use of opioids for >3 months) Allergy to local anesthetics Pre-existing neuropathy or weakness of the operative limb Any neuromuscular disorder Diabetes type I and II Contraindication to a femoral nerve block or adductor canal nerve block Allergy or intolerance to any of the study medications BMI > 35 kg/m2

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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 |
| --- | --- |
| Experimental: High volume Adductor canal block<br>Adductor canal block performed in the distal thigh (1/3 of the total distance between the superior border of the patella and the femoral crease, cephalad to the patella) utilizing an injectate volume of 30 mL 0.25% bupivacaine/ epinephrine | Procedure: High Volume Adductor Canal Block<br>* Adductor canal block performed in the distal thigh (1/3 of the total distance between the superior border of the patella and the femoral crease, cephalad to the patella) utilizing an injectate volume of 30 mL 0.25% bupivacaine/ epinephrine<br>|
| Experimental: Low volume Adductor Canal Block<br>Adductor canal block performed in the distal thigh (1/3 of the total distance between the superior border of the patella and the femoral crease, cephalad to the patella) utilizing an injectate volume of of 10 mL 0.75% bupivacaine/ epinephrine | Procedure: Low Volume Adductor Canal Block<br>* Adductor canal block performed in the distal thigh (1/3 of the total distance between the superior border of the patella and the femoral crease, cephalad to the patella) utilizing an injectate volume of of 10 mL 0.75% bupivacaine/ epinephrine<br>|
| Experimental: Femoral nerve block<br>Femoral nerve block with 10 mL 0.75 % bupivacaine/epinephrine | Procedure: Femoral Nerve Block<br>* Femoral nerve block with 10 mL 0.75 % bupivacaine/epinephrine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quadriceps function as assessed by non-invasive transcutaneous nerve stimulation of the femoral nerve | After CSE effect, but prior to peripheral block, quadriceps function will be assessed by non-invasive transcutaneous nerve stimulation of the femoral nerve by placing an ECG electrode over the femoral location (determined by U/S) in the inguinal groove. The threshold amperage that produces patellar motion in response to electrical stimulation will be recorded. This threshold amperage will serve as a baseline value. Following the peripheral nerve block, transcutaneous stimulation will be repeated and, if still possible to elicit quadriceps contractions in response to electrical stimulation, the resulting new threshold amperage will be measured. The new threshold amperage will be expressed as a percentage of the baseline value and serve as a quantitative functional indication of the extent of quadriceps paresis resulting from the peripheral nerve block. The primary outcome will be quadriceps paralysis - yes/no. | 15 minutes after the placement of the peripheral nerve block (femoral or adductor canal) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Threshold amperage as a percentage of the baseline value | Following the peripheral nerve block, transcutaneous stimulation will be repeated and, if still possible to elicit quadriceps contractions in response to electrical stimulation, the resulting new threshold amperage will be measured. The new threshold amperage will be expressed as a percentage of the baseline value and serve as a quantitative functional indication of the extent of quadriceps paresis resulting from the peripheral nerve block. | 15 minutes after the placement of the peripheral nerve block | 
| Analgesic adequacy | Analgesic adequacy as determined by pain scores (0-10) at spinal resolution (on average 2 hours post-op), 24 hours post-op and 48 hours post-op and daily epidural patient controlled analgesia consumption | Resolution of the spinal anesthetic (2 hours post-op), 24 and 48 hours post-op | 
| Ability to complete a straight leg lift | Ability to complete and hold (for 3 seconds) a straight leg lift (from supine position) against gravity as evidence of meaningful quadriceps function - performed in holding area (baseline), at spinal resolution (on average 2 hours post-op), 24 hours post-op and 48 hours post-op | Holding area (baseline), at spinal resolution (2 hours post-op), 24 hours post-op and 48 hours post-op | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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adductor canal, femoral, quadriceps