Adductor Canal Block After Total Knee Replacement - a Suture-method Catheter vs a Standard Catheter vs a Single Bolus

Study Overview
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Brief Summary
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In this study we wish to investigate the analgesic effect of the administration of 0.2% ropivacaine for an adductor canal block as repeated boluses (20 ml every 8 hours) through a new suture-method catheter or a standard perineural catheter compared with a single bolus (20 ml), in patients following primary total knee arthroplasty.

Detailed Description
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The aim of the study is to compare the clinical effects of three different administration forms for an ACB: repeated intermittent boluses through a Certa catheter (CC) versus repeated boluses through a standard catheter (through the needle) (SC) versus a single bolus (SB). Our dual hypothesis is that repeated boluses through a catheter (either Certa or standard catheter) reduces opioid consumption (primary outcome), as well as reduces pain scores, enhances ambulation and muscle strength compared with a single bolus, and that the Certa catheter is superior to a standard catheter.

Official Title
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Comparison of the Analgesic Effect of an ACB (Adductor Canal Block) Using a New Suture-method Catheter vs a Standard Perineural Catheter vs a Single Bolus: A Randomized, Blinded, Controlled Study

Conditions
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Pain Management

Intervention / Treatment
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* Drug: Initial bolus (Certa and standard catheter groups)
* Drug: Initial bolus (Single bolus group)
* Drug: Intermittent boluses (Certa and standard catheter groups)
* Drug: Intermittent boluses (Single bolus group)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients scheduled for unilateral total knee arthroplasty in spinal anesthesia Patients who gave their written informed consent to participating in the study after having fully understood the contents of the protocol and restrictions ASA 1-3 Ability to perform a TUG test preoperatively Exclusion Criteria: Patients who cannot cooperate Patients who cannot understand or speak Danish. Patients with allergy to the medicines used in the study Patients with a daily intake of strong opioids (morphine, oxycodone, ketobemidone, methadone, fentanyl) during the last 4 weeks Patients suffering from alcohol and/or drug abuse - based on the investigator's assessment Rheumatoid arthritis BMI > 40 Neuromuscular pathology in the lower limbs Pregnancy

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
Interventional Model Description: The study is performed as a blinded, randomized, controlled study. Randomization will be based on a computer-generated block randomization list in a 1:1:1 ratio, block sizes of 9. A person, not otherwise involved in the study, will prepare the randomization list and keep it, locked away in a secure place. 2 sets of consecutively numbered, sealed, opaque, code envelopes will be prepared by the same person.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Certa Catheter<br>A Certa-catheter (suture method) is inserted under ultrasound guidance at the midthigh level in the adductor canal, using an in plane technique, short/oblique axis view. A bolus of ropivacaine will be administered during real time US imaging to ensure correct placement of the catheter (initial bolus). An infusion pump will be connected immediately following catheter insertion, delivering intermittent boluses every 8 hours until 12 pm on POD2. 2 dressings will be applied (medial and lateral) to obscure which catheter has been placed. | Drug: Initial bolus (Certa and standard catheter groups)<br>* 10 ml of ropivacaine 0,75% will be used to ensure correct position of the needle and to expand the adductor canal, followed by injection of another 10 ml of ropivacaine 0.75% via the catheter during real time US imaging to ensure correct placement of the catheter.<br>Drug: Intermittent boluses (Certa and standard catheter groups)<br>* 20 ml of ropivacaine 0.2% every 8 hour in the catheter<br>|
| Active Comparator: Standard Catheter<br>A Standard-catheter is inserted under ultrasound guidance at the midthigh level in the adductor canal, using an in plane technique, short/oblique axis view. A bolus of ropivacaine will be administered during real time US imaging to ensure correct placement of the catheter (initial bolus). An infusion pump will be connected immediately following catheter insertion, delivering intermittent boluses every 8 hours until 12 pm on POD2. 2 dressings will be applied (medial and lateral) to obscure which catheter has been placed. | Drug: Initial bolus (Certa and standard catheter groups)<br>* 10 ml of ropivacaine 0,75% will be used to ensure correct position of the needle and to expand the adductor canal, followed by injection of another 10 ml of ropivacaine 0.75% via the catheter during real time US imaging to ensure correct placement of the catheter.<br>Drug: Intermittent boluses (Certa and standard catheter groups)<br>* 20 ml of ropivacaine 0.2% every 8 hour in the catheter<br>|
| Active Comparator: Single Bolus<br>A bolus of ropivacaine will be injected into the adductor canal, at the midthigh level, using a 80 mm x 22G Pajunk needle during real time US imaging (initial bolus). A sham catheter (25 Certa and 25 standard catheters according to randomi-zation) will be fixed externally and covered by dressings as in the catheter groups groups (Certa and standard). Care will be taken to use approximately the same amount of time as used in the catheter groups (Certa and standard) An infusion pump will be connected immediately following catheter insertion, delivering intermittent boluses into the dressing every 8 hour until 12 PM on POD2. | Drug: Initial bolus (Single bolus group)<br>* 20 ml of ropivacaine 0.75%<br>Drug: Intermittent boluses (Single bolus group)<br>* 0.1ml of ropivacaine 0.2% every 8 hour in the sham catheter<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total opioid consumption | • Total opioid consumption (PCA pump and any potential rescue administration) between groups (SB vs CC, SB vs SC and CC vs SC) | from end of surgery until 12 (noon) on POD 2 (Postoperative Day) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VAS (Visual analog scale) flexion | VAS pain score (0-100mm) during 45 degrees active knee flexion | o Pain is recorded preoperatively before administration of medication, and postoperatively at the PACU (Postoperative Care Unit), at 8 PM on the day of surgery, at 8 AM, 12 (noon) and 8 PM on POD 1 and finally at 8 AM and 12 (noon) on POD 2. | 
| VAS rest | VAS pain score (0-100mm) during rest | o Pain is recorded preoperatively before administration of medication, and postoperatively at the PACU, at 8 PM on the day of surgery, at 8 AM, 12 (noon) and 8 PM on POD 1 and finally at 8 AM and 12 (noon) on POD 2. | 
| VAS-TUG (Time-Up-and-Go-Test) | Worst VAS pain score (0-100mm) during Timed-Up-and-Go test | 12 (noon) on POD 1 and 2 | 
| TUG-test | Timed-Up-and-Go test | 12 (noon) on POD 1 and 2 | 
| 6 minutes walk test | How many meters the patient can walk (using a high 4-wheel walker) in 6 minutes | 12 (noon) on POD 1 and 2 | 
| MVIC (Maximum Voluntary Isometric Contraction) | Quadriceps strength assessed as maximum voluntary isometric contraction in percentage of preoperative baseline values. | Preoperatively and at 12 (noon) on POD 1 and 2 | 
| TUG test, patient number | Number of patients able to perform the TUG test using a high 4-wheel walker | 12 (noon) on POD 1 and 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pain, Total knee arthroplasty, Regional anesthesia