Can Single-Injection Adductor Canal Blocks Improve PostOp Pain Relief in Patients Undergoing Total Knee Arthroplasty?

Study Overview
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Brief Summary
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The purpose of the study is to determine the effect of a single injection adductor canal block (ACB) on pain scores within 24 hours post total knee arthroplasty (TKA).

Detailed Description
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Total knee arthroplasty (TKA), also known as total knee replacement, has been associated with a significant pain burden in the postoperative period. Methods to manage pain associated with this operation have in the past included injecting pain medication into the epidural space of the spinal cord, around a peripheral nerve, around the space surrounding the joint, or a combination of pain management techniques. In recent years, the femoral nerve block (injection of pain medication around the peripheral nerve, specifically the femoral nerve) has been proposed as an effective way to manage pain while sparing many of the undesirable side effects of narcotic pain medications. Traditional techniques of the femoral nerve block involve the injection of pain medication around the peripheral nerve at the level of the groin area. A nerve block at this point in the path of the femoral nerve affects all of the musculature of the front part of the thigh as well as the nerves responsible for sensation to the majority of the knee joint. The femoral nerve block performed at the level of the groin provides an excellent level of pain relief at the knee joint, but is also associated with weakness of the quadriceps muscle. The resultant quadriceps weakness can both slow the physical therapy process and be a risk factor for post-operative falls. Participation in physical therapy is a critical component of the rehabilitation process and is started as soon as tolerated by the patient. The ideal pain management technique would provide the same degree of pain relief as the femoral nerve block while preserving the strength in the front part of the thigh muscles. One suggested technique to achieve both of these goals is the injection of a large volume dilute local pain medication mixture around the joint during surgery. This has been used as a substitute to provide pain relief around the joint while maintaining strength in the quadriceps muscle and the ability to participate in physical therapy. This technique however, does not last long since the medication disperses away from the joint space. A variation of the femoral nerve block in the lower thigh, within a space called the adductor canal, has been demonstrated to provide equivalent amounts of pain relief as a proximal femoral nerve block along with preservation of motor function to the quadriceps muscle. What is not as well-established is whether the combination of injecting pain medication directly around the joint space in the knee along with a single injection of pain medication in the adductor canal in the lower thigh can improve pain scores and extend the duration of pain relief provided compared to only an injection around the joint space.

Official Title
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Does Single Injection Adductor Canal Block Improve Postoperative Analgesia in Patients Receiving Periarticular Local Anesthesia Injections for Total Knee Arthroplasty?

Conditions
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Pain Management

Intervention / Treatment
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* Other: ACB Control - 20 ml saline injection for ACB
* Drug: ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block
* Drug: Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and Females age 18+ years old having total knee arthroplasty (TKA) at UCI Medical Center American Society of Anesthesiologists physical status I to III Exclusion Criteria: Allergy to local anesthetics Pregnancy Nursing Mothers Children <18 years of age Renal impairment (GFR<60 mL/min/1.73m2) Hepatic Impairment (active hepatitis, elevated AST or ALT, jaundice) Opioid tolerant patients (defined as greater than 30 mg Morphine equivalent consumed daily) Patients that are diabetic with peripheral neuropathy BMI greater than 40

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: Supportive Care
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ACB Control + Local Infiltration<br>ACB Control - 20 ml saline injection for ACB + Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline | Other: ACB Control - 20 ml saline injection for ACB<br>* Adductor Canal Block Control (20 ml saline injection)<br>Drug: Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline<br>* 100 mLs of a solution containing: Ropivacaine 2 mg/mL (49.25 mL) + Epinephrine 1 mg/mL (0.5 mL) + Ketorolac 30mg/mL (1mL) + Clonidine 100 mcg/mL (0.8 mL) + 0.9% Normal saline (48.45 mL)<br>|
| Experimental: ACB Study + Local infiltration<br>ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block + Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline | Drug: ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block<br>* Adductor Canal Block Study (20 ml 0.5% Ropivacaine)<br>Drug: Local infiltration - 100 mLs of a solution containing: Ropivacaine + Epinephrine + Ketorolac + Clonidine + 0.9% Normal saline<br>* 100 mLs of a solution containing: Ropivacaine 2 mg/mL (49.25 mL) + Epinephrine 1 mg/mL (0.5 mL) + Ketorolac 30mg/mL (1mL) + Clonidine 100 mcg/mL (0.8 mL) + 0.9% Normal saline (48.45 mL)<br>|
| Experimental: ACB Study Only<br>ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block | Drug: ACB Study - 20 ml 0.5% Ropivacaine for Adductor Canal Block<br>* Adductor Canal Block Study (20 ml 0.5% Ropivacaine)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Score | The primary outcome variable of interest is the average maximum pain score within 24 hours postoperative. | within 24 hours postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioid Use | 24 Hour post-surgical opioid use | within 24 hours postoperative | 
| PACU Opioid Use | PACU opioid use | Postoperative (while in PACU), an expected average of 60 minutes | 
| Daily Opioid Use | Average daily opioid use during hospitalization | duration of hospital stay, an expected average of 3 days | 
| Average NRS Pain Score | Average NRS pain score | within 24 hours postoperative | 
| Length of Stay | Length of hospital stay | duration of hospital stay, an expected average of 3 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pain management for total knee arthroplasty