Postoperative Knee Strength Following Total Knee Replacement: A Double-Blinded Randomized Comparison Study

Study Overview
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Brief Summary
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Major surgery involving the knee is often associated with severe postoperative pain. Postoperative pain control remains a significant contributor to delayed recovery and length of hospital stay. Approaches to minimize postoperative pain after surgery are a matter of major concern due to the need for early mobilization, a crucial factor in good postoperative rehabilitation. Femoral nerve blocks by either continuous infusion or single injection of anesthetics provide an effective method for analgesia while minimizing the need for systemic opioid therapy, reducing the opioid induced side effects, and facilitating early ambulation. Administration of fentanyl has shown to be a highly effective method to control pain after Total Knee Replacement (TKR). The investigators hypothesize that fentanyl infusions will result in greater post-operative strength in the operative knee.

Detailed Description
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All subjects scheduled to receive a unilateral, primary total knee replacement were evaluated for eligibility in the preoperative anesthesia center. Adults, older than 18 years of age, ASA I-III were included in the study. Subjects who were either pregnant, on anticoagulant therapy, allergic to opioids, local anesthetics, chronic pain patients, history of traumatic lower extremity injury, or had a body mass index of greater than 35 kg/m2 were excluded from the study.

Official Title
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Postoperative Knee Strength Following Total Knee Replacement: A Double-Blinded Randomized Comparison Study

Conditions
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Total Knee Replacement, Primary Knee Arthroplasty

Intervention / Treatment
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* Drug: Fentanyl
* Drug: Ropivacaine
* Drug: Fentanyl


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing unilateral primary total knee replacement ASA class I-III 18 years and older Exclusion Criteria: Patient refusal Pregnancy Coagulopathy Adverse/allergic reaction to any opioids or local anesthetics History of long-term opioid use (greater than 60 days) Infection Traumatic lower extremity injury

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Femoral Nerve Fentanyl<br>Fentanyl 3 µg/ml delivered continuously through a femoral nerve sheath catheter for 24 hours post-total knee replacement. All study drugs were continuously infused for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU). | Drug: Fentanyl<br>* Fentanyl 3 µg/ml continuously infused for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU)through a femoral nerve sheath catheter.<br>|
| Active Comparator: Femoral Nerve Ropivacaine<br>Ropivacaine 0.1% continuously delivered through a femoral nerve sheath catheter for 24 hours post-total knee replacement. All study drugs were continuously infused for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU). | Drug: Ropivacaine<br>* Ropivacaine 0.1% delivered through a femoral nerve sheath catheter continuously for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU).<br>|
| Placebo Comparator: Intravenous Fentanyl with placebo<br>Control group which received 0.9% normal saline delivered through a femoral nerve sheath catheter in addition to a continuous intravenous infusion of fentanyl 3 µg/ml via a PCA pump. All study drugs were continuously infused for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU). | Drug: Fentanyl<br>* 0.9% normal saline delivered through a femoral nerve sheath catheter in addition to a continuous intravenous infusion of fentanyl 3 µg/ml via a PCA pump for a 24 hour period at a basal rate of 10ml/hour starting from the time the patient entered the post anesthesia care unit (PACU).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of Postoperative Strength (Extension) | To assess extension force postoperatively to discern differences in muscle strength retention between continuous femoral nerve sheath catheter administration of fentanyl or Ropivacaine or a continuous IV infusion of fentanyl. | 24 hours post-surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VAS Scores and Postoperative Supplemental Morphine Consumption | Secondary Objective To determine the amount of required supplemental analgesia during the postoperative period. To determine postoperative analgesia using a Visual Analog Scale (VAS) 0 - 10 centimeter line. | 24 hours post-surgery | 
| Serum Fentanyl Levels | To identify a difference in serum fentanyl levels among the groups. | 24 hours post-surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Regional Anesthesia, Post-operative pain management, Femoral Nerve Block, Total Knee Replacement