Comparison of Continuous Femoral Nerve Block and Adductor Canal Block After Total Knee Replacement Therapy

Study Overview
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Brief Summary
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The blockade of the femoral nerve (FNB) is the most common postoperative pain therapy after total knee replacement. Because of motor-driven weakness of the quadriceps muscle induced by femoral nerve block mobilization of Patients is difficult even dangerous (falls) and hospital stays are extended. An alternative method could be an adductor canal block (ACB). Anatomical studies of the adductor canal demonstrated that the adductor canal contains the saphenous nerve, a pure sensory nerve for medial and anterior aspects of the knee and the tibia without any motor function. This prospective, double-blinded, randomized study investigates the effect of FNB and ACB on quadriceps motor weakness and analgesia determined by Numeric Rating Scale (NRS). We expect the ACB to be superior in muscle strength but equal in pain score. Both groups receive an additional anterior sciatic nerve block for complete sensory block of the operated knee

Official Title
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Randomized Controlled Study: Comparison of Continuous Femoral Nerve Block and Adductor Canal Block After Total Knee Replacement Therapy Relating to Early Mobilization and Analgesia

Conditions
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Total Knee Arthroplasty, Total Knee Replacement, Femoral Nerve Block, Adductor Canal Block

Intervention / Treatment
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* Drug: Ropivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with knee replacement therapy and general anaesthesia informed consent preoperative timed up and go test performable Exclusion Criteria: emergency patients BMI > 40 kg/m2 American Society of Anaesthesiologists physical status (ASA) 4-5 severe chronic obstructive pulmonary disease (COPD) rheumatic arthritis, diabetic Polyneuropathy, M. Parkinson nerve injury of lumbosacral plexus coagulopathy with bleeding tendency not capable of speaking or understanding german or english

Ages Eligible for Study
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Minimum Age: 50 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 |
| --- | --- |
| Active Comparator: Continuous Adductor Canal Block (CACB)<br>Continuous Adductor Canal block performed with: loading dose 0,375% Ropivacaine 15ml (56,25mg) start infusion 0,2% Ropivacaine 6ml/h Procedure: Femoral Nerve Block. Adductor Canal Block Drug: Ropivacaine | Drug: Ropivacaine<br>* Regional Anesthesia performed with 0.375% Ropivacaine 15ml (56,25mg)<br>|
| Active Comparator: Continuous Femoral Nerve Block (CFNB)<br>Continuous Femoral Nerve Block performed with: loading dose 0,375% Ropivacaine 15ml (56,25mg) start infusion 0,2% Ropivacaine 6ml/h Procedure: Femoral Nerve Block. Adductor Canal Block Drug: Ropivacaine | Drug: Ropivacaine<br>* Regional Anesthesia performed with 0.375% Ropivacaine 15ml (56,25mg)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Timed-Up and Go-test for mobility evaluation | The patient is observed and timed while he rises from an arm chair, walks 3 meters, turns, walks back, and sits down again. | third postoperative day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Scores | Numeric Rating Scale (NRS), 0-10 for Rest / Stress. in Addition total Body NRS Pain | 6, 24, 48, 72 hours postoperative | 
| Quadriceps strength | Numeric Scale (0-5) | 6, 24, 28, 72 hours postoperative | 
| Ropivacaine consumption (each catheter) | Measurement of the total amount | 24, 48, 72 hours postoperative | 
| CAS (Cumulated Ambulation Score) | Cumulated Ambulation Score is calculated with routine data. Measurement for ambulation ability | 24,48,72 hours postoperative | 
| Mobility Score (MoSc) | Is calculated with routine data. Measurement for overall mobilization (none- passive mobilization, sitting, standing, walking with walking device, walkin free or with crutches) | 24,48,72 hours postoperative | 
| Analgesic regimen | Documentation of analgesic prescriptions and rescue medications during postoperative course | preop and 0, 6 , 24, 48, 48 hours postoperative |