Clinical trial NCT06908837: Effects of 10 Versus 20 mL Local Anesthetic for Popliteal Plexus Block on Opioid Consumption, Pain, and Patient-Reported Outcomes After Total Knee Arthroplasty
Official title: Effects of 10 Versus 20 mL Local Anesthetic for Popliteal Plexus Block on Opioid Consumption, Pain, and Patient-Reported Outcomes After Total Knee Arthroplasty
        - a Randomized, Controlled, Blinded Study
Study type: INTERVENTIONAL
Overall status: ENROLLING_BY_INVITATION
Phase: PHASE4
Conditions: Total Knee Arthroplasty
Regional Anesthesia
Multimodal Analgesic Approach
Postoperative Opioid-related Complications
Keywords: Popliteal Plexus Block
Total knee arthroplasty
regional anesthesia
optimal analgesic volume
postoperative pain
postoperative opioid consumption
Quality of Recovery 15
Manual Muscle Test
Postoperative mobility
Lead sponsor: Regionshospitalet Silkeborg
Sponsor class: OTHER
First posted: 2025-04-03
Enrollment: 120
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: This single-centre, blinded, controlled, randomized clinical trial follows a parallel design, with one group receiving a PPB with 10 mL of bupivacaine 5 mg/mL and the other group receiving a PPB with 20 mL of bupivacaine 5 mg/mL. A total of 120 patients will be included and allocated in a 1:1 ratio using computer-generated block randomization (blocks of 10).
Primary purpose: TREATMENT

Brief summary: This trial aims to assess the analgesic effect of Popliteal Plexus Block (PPB) with 10 mL versus 20 mL of Bupivacain 5 mg/mL, when applied as an adjunct treatment to a multimodal analgesic regimen following primary total knee arthroplasty. We hypothesize that PPB with 20 mL of local anesthetic reduces 24-hour postoperative opioid consumption (= primary outcome) compared to 10 mL after TKA.

Secondary outcome include

* the frequency of 24-hour opioid-free analgesia
* pain intensity at rest and during mobilization
* Manual Muscle Tests and ability to mobilize with crutches six hours after end-of-surgery
* and patients reported outcomes using the Quality of Recovery 15 survey 24 hours after end-of-surgery.

Participant will:

* undergo primary total knee arthroplasty in spinal anesthesia.
* recieve a PPB with either 10 mL of Bupivacaine or 20 mL.
* recieve a multimodal analgesic regime including a Femoral Triangle Block.
* Have 10 scored morphine tablets available for self-administration within the first 24 postoperative hours after end-of-surgery.
* be examined by a physiotherapist 6 hours (±1 hour) after end-of-surgery to assess pain scores, manual muscle testing of ankle and knee function, and the ability to mobilize with crutches.
* complete a survey 24 hours after end-of-surgery to assess self-administered morphine intake, pain scores, and Quality of Recovery-15.

Detailed description: Patients will undergo primary unilateral total knee arthroplasty with insertion of non-cruciate retaining standard cemented prosthesis by a parapatellar medial approach, without use of tourniquet or Local Infiltration Analgesia.

For the spinal anesthesia, 3 mL of Ropivacaine 5 mg/ml will be applied.

All patients will receive a femoral triangle block in combination with the PPB, both administered immediately after surgery in the post-anesthesia care unit.

Description of the PPB procedure:

The superficial femoral artery is identified at mid-thigh level and traced caudally until it deviates from sartorius muscle and is positioned adjacent to the posteromedial margin of the vastus medialis muscle, close to the adductor hiatus. The needle will be inserted medially to the transducer and advanced in-plane through the sartorius muscle targeting the endpoint of injection in the distal part of the adductor canal, on the top of the superficial femoral artery, posteromedial to the fascia of the vastus medialis muscle. We will inject the allocated volume of bupivacaine 5 mg/mL, ensuring anterolaterally spread to the artery

The Femoral Triangle Block uses 15 mL of Bupivacaine 5 mg/mL (10 mL applied in the femoral triangle to target the saphenous nerve and nerve to vastus medialis and 5 mL applied to target the intermediate femoral cutaneous nerve located at the superficial side of the sartorius muscle).

The multimodal analgesic regime also consists of a Dexamethasone 12 mg IV (administered perioperatively), Paracetamol (1000 mg) x 4 daily + NSAID (400 mg) x 3 times daily postoperatively, inclusing preoperatively administration of Paracetamol 1000 mg and Ibuprofen 400 mg.

The scored morphine tablets allows the patients to take 5 mg morphine at a time, with a maximum oral dose of 100 mg within the first 24 hours after end-of-surgery time. If needed, hospital staff can administer rescue doses of intravenous morphine, which will be recorded in the patient file. Total opioid consumption will be reported as oral morphine milligram equivalents (MME), combining hospital-administered opioid doses from the patient file and self-reported intake of dispensed morphine tablets.

Eligibility criteria: Inclusion Criteria:

* Scheduled to undergo primary total knee arthroplasty in spinal anesthesia.
* Ability to give their written informed consent after having fully understood the contents of the study.
* American Society of Anesthesiologists (ASA) physical status 1, 2, or 3.

Exclusion Criteria:

* Patients who cannot read or speak Danish.
* Patients who cannot operate or have access to a smartphone with internet connectivity (required for patient-reported outcome assessment).
* Patients with allergies or intolerance to the medicines used in the study.
* Patients with a consistent daily intake of opioids preoperatively.
* Patients who are dependent on walking aid devices preoperatively.
* Patients suffering from alcohol and/or drug abuse - based on the investigator's assessment.
* BMI \> 40.
* Diagnosed with chronic neurodegenerative disorders.

Primary outcomes:
measure: Total opioid consumption, expressed in oral morphine milligram equivalents (MME).
timeFrame: From T0 (end-of-surgery time) to T24 (24 hours after end-of-surgery time)
Secondary outcomes:
measure: No opioid requirement
timeFrame: From T0 (end-of-surgery time) to T24 (24 hours after end-of-surgery time)
measure: Pain at rest
timeFrame: Assessed preoperatively, at T6 (6±1 hours after end-of-surgery time), and at T24 (24 hours after end-of-surgery time).
measure: Pain during 10 meters walk assisted only by crutches
timeFrame: Assessed preoperatively, at T6 (6±1 hours after end-of-surgery time), and at T24 (24 hours after end-of-surgery time).
measure: Early postoperative walking ability
timeFrame: Assessed at T6 (6±1 end-of-surgery time)
measure: Postoperative Manual Muscle Test
timeFrame: Assessed at T6 (6±1 end-of-surgery time)
measure: Quality of Recovery 15
timeFrame: Assessed at T24 (24 hours after end-of-surgery time)
Other outcomes:
Locations:
city: Silkeborg
country: Denmark
facility: Elective Surgery Centre at Silkeborg Regional Hospital
state: Denmark Central Region
Study officials:
affiliation: Elective Surgery Centre at Silkeborg Regional Hospital, Denmark
name: Johan K Sørensen, MD
role: PRINCIPAL_INVESTIGATOR
References: