Combination of Nerve Blocks and Local Infiltration Analgesia in Knee Arthroplasty (BALIA)

May 4, 2026 updated by: Region Skane

Postoperative Analgesia in Patients Undergoing Knee Replacement Surgery - a Study Comparing Intraoperative Local Infiltration Analgesia Only With Ultrasound-guided Nerve Blocks Added to Intraoperative Local Infiltration Analgesia, a Randomized Clinical Trial

The aim of this clinical randomized trial is to compare local infiltration analgesia (LIA) alone versus the combination of LIA with saphenous nerve (SN) block, block of the nerve to vastus medialis (NVM), and anterior femoral cutaneous nerve (AFCN) block in participants undergoing total knee arthroplasty (TKA). The primary outcome is pain intensity, measured using the Numerical Rating Scale (NRS) at multiple time points after surgery. Secondary outcomes include opioid consumption, time to mobilization, postoperative nausea and vomiting, length of hospital stay, neurological complications and differences in opioid consumption and NRS pain scores between general and spinal anesthesia.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Scientific Rationale and Background Total Knee Arthroplasty (TKA) requires effective perioperative pain management. Traditionally, Local Infiltration Analgesia (LIA)has been the standard method, sometimes combined with femoral nerve block. However, femoral nerve block impairs quadriceps motor function, making early mobilization-critical for postoperative rehabilitation-difficult for participants.

Recent advances have introduced purely sensory nerve block techniques that preserve motor function. The knee joint innervation is complex and involves multiple neural pathways. The Saphenous Nerve (SN), Nervus Vastus Medialis (NVM), and the Anterior Femoral Cutaneous Nerve (AFCN) are all branches of the femoral nerve that provide sensory innervation to the knee without contributing to motor control of the quadriceps. The adductor canal contains the SN and NVM, which are primarily sensory nerves. The AFCN travels superficially in the femoral triangle and innervates the skin of the anterior and medial thigh.

Studies have shown that adductor canal block (targeting SN and NVM) combined with LIA provides comparable pain relief to femoral nerve block without motor impairment. Additionally, the AFCN contributes to sensory innervation of the anterolateral and anteromedial aspects of the knee joint. Our hypothesis is that combining these three sensory blocks (SN, NVM, and AFCN) with LIA may provide superior pain control and reduced opioid consumption compared to LIA alone, while preserving motor function necessary for early mobilization.

Primary Research Questions

  1. Does the combination of the SN block, the NVM block of and the AFCN block togheter with LIA provide better postoperative pain control compared to LIA alone?
  2. Does the above combination reduce total postoperative opioid consumption? Secondary Research Questions
  1. Does the nerve block combination facilitate earlier postoperative mobilization?
  2. Does it reduce the incidence of postoperative nausea and vomiting?
  3. What is the incidence of neurological complications (sensory deficits and motor impairment)?
  4. Does the intervention affect length of hospital stay?

Randomization and Allocation Procedure Randomization is conducted the day before surgery by the responsible anesthesiologist using a computer-generated randomization sequence. The anesthesiologist draws a sealed randomization envelope containing the group allocation. The envelope accompanies the patient's medical record and case report forms (CRFs ) throughout the hospital stay and is verified in the operating room by the anesthesiologist.

Anesthesia type (general anesthesia with propofol and remifentanil using TCI (Target Controlled Infusion) with Eleveld pharmacokinetic model, or spinal anesthesia with 0.5% bupivacaine) is determined by clinical indication and is independent of randomization.

Arms and Interventions All patients receive standardized multimodal analgesia preoperatively: etoricoxib, paracetamol, oxycodone, and betamethasone.

Intervention Arm: Nervus Vastus Medialis (NVM) block + Saphenous Nerve (SN) block + Anterior Femoral Cutaneous Nerve (AFCN) block + Local Infilration Analgesia (LIA) All nerve blocks are performed under ultrasound guidance with strict sterile precautions.

  1. NVM block:

    • In-plane ultrasound approach using a linear high-frequency transducer
    • Needle inserted from the lateral thigh, placed between vastus medialis and sartorius, lateral to the adductor membrane
    • Injection: 5 ml ropivacaine 5% with clonidine 1.875 micrograms per ml
    • NVM is visualized and surrounded by local anesthetic

  2. SN block:

    - Same needle entry point as NVM block

    • Needle retracted and advanced toward the lateral border of the femoral artery
    • Sartorius posterior fascia is perforated; needle tip placed beside the SN
    • Injection: 10 ml ropivacaine 0.5% with clonidine 1.875 micrograms per ml
    • Hydrodissection of the adductor canal is observed; SN is completely surrounded by local anesthetic

  3. AFCN block:

    - AFCN divides into multiple branches at the level of the femoral triangle

    - Nerves are located superficially above the superior sartorius fascia in loose subcutaneous fascia

    • Typically, 3-4 individual nerve branches are visualized
    • Needle retracted in-plane from the adductor canal approach
    • Individual branches blocked superficially above sartorius
    • Injection: 1 ml ropivacaine 5% with clonidine 1.875 micrograms per ml per branch

  4. LIA:

    - LIA is administered by the surgeon before wound closure

    - 150 ml ropivacaine 2 mg/ml with 0.5 mg adrenaline is infiltrated periarticular around the knee capsule, collateral ligaments, under the patella, and subcutaneously

    Control Arm: LIA Only

    - LIA is administered by the surgeon before wound closure

    - 150 ml ropivacaine 2 mg/ml with 0.5 mg adrenaline is infiltrated periarticular around the knee capsule, collateral ligaments, under the patella, and subcutaneously

    Enrollment Planned Total Enrollment: 200 patients

    Principal Investigators:

    • Fredrik Fellert, MD, DESA, EDIC, EDEC, PhD student, Senior Consultant, VO Planned Operations, Trelleborg Hospital, Lund University, Sweden

    • Andreas Ekman, MD, PhD, DEAA, Senior Consultant, VO Planned Operations, Trelleborg Hospital, Lund University, Sweden
    • Fredrik Sjövall, MD, Associate Professor, Senior Consultant, Department of Perioperative and Intensive Care, Malmö University Hospital, Lund University, Sweden
    • Gunnar Flivik, MD, Associate Professor, Senior Consultant, Department of Orthopedics, Lund university Hospital, Lund University, Sweden

    Ethical Approval Ethics Committee: Swedish Ethical Review Authority (Etikprövningsmyndigheten) Approval Reference: 2025-06626-01 Approval Date: 2025-10-30 This study is conducted in accordance with the Declaration of Helsinki and applicable Swedish regulations for clinical research, including the Act on Ethical Review of Research Involving Humans (2003:460).

    Statistical Considerations:

    A priori sample size calculation was performed using a two-sample t test with a significance level (alpha) of 0.05 and statistical power of 0.80, assuming a between-group difference of 2 points on the NRS pain scale. This yielded an estimated requirement of 90 participants per group to achieve adequate power. Data will be analyzed using SPSS. Descriptive statistics will be presented as appropriate for the distribution of each variable. Group comparisons will be performed using chi-square test or Fisher's exact test for categorical variables, and independent-samples t test or Mann-Whitney U test for continuous variables, depending on assessment of normality.

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Sweden
      • Trelleborg, Sweden
        • Recruiting
        • Department of Anaesthesiology, Trelleborg Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

-Undergoing primary unilateral total knee arthroplasty

Exclusion Criteria:

  • Pregnancy
  • Coagulopathy or other bleeding disorder that precludes regional anesthesia
  • Allergy to local anesthetics
  • Inability to understand spoken and written Swedish
  • Unwillingness to participate in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Intervention Arm-Nerve blocks in addition to Local Infiltration Analgesia

Ultrasound guided nerve blocks are administered preoperatively in addition to the Local Infiltration Analgesia administered during surgery.

Nerve blocks used:

  1. Nerve to Vastus Medialis (NVM) block:

    Injection: 5 ml ropivacaine 5% with clonidine 1.875 micrograms per ml

  2. Saphenous Nerve (SN) block:

    Injection: 10 ml ropivacaine 0.5% with clonidine 1.875 micrograms per ml

  3. Anterior Femoral Cutaneous Nerve (AFCN) Block:

AFCN divides into multiple branches at the level of the femoral triangle Injection: 1 ml ropivacaine 5% with clonidine 1.875 micrograms per ml per branch

Local Infiltration Analgesia (LIA):

150 ml ropivacaine 2 mg/ml with 0.5 mg adrenaline is infiltrated periarticular around the knee capsule, collateral ligaments, under the patella, and subcutaneously
Drug: Ropivacain 5 mg/ml + Clonidine
Drug used in the block
No Intervention: Control arm - Local Infiltration Analgesia only

No ultrasound guided nerve blocks are administered. Local Infiltration Analgesia (LIA) is the same as in the- intervention arm:

150 ml ropivacaine 2 mg/ml with 0.5 mg adrenaline is infiltrated periarticular around the knee capsule, collateral ligaments, under the patella, and subcutaneously

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Pain Intensity: Measured using the NRS scale 0-10 at multiple predefined time points postoperatively (1 hour, 4 hours, 24 hours)
Time Frame: The day of surgery, postop day 1 and 14 days post-surgery
Pain intensity was assessed using the Numeric Rating Scale (NRS) upon arrival at the post anesthesia care unit (PACU) and at 1, 2, 3 and 4 hours post-PACU admission, as well as at ward admission, on the evening of the surgery day, the morning of Postoperative Day 1 (POD1), and at discharge. At the post-surgery visit at 14 days NRS was also assessed.
The day of surgery, postop day 1 and 14 days post-surgery
Difference in analgesia consumption
Time Frame: The day of surgery, postop day 1 and 14 days post-surgery
Total Postoperative Opioid Consumption: Cumulative morphine equivalents (mg) recorded during hospitalization (intraoperative and postoperative period).
The day of surgery, postop day 1 and 14 days post-surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to mobilization
Time Frame: The day of surgery, postop day 1
Time to First Mobilization: Time (hours) from arrival to the PACU to first mobilization (sitting, standing, or walking as tolerated)
The day of surgery, postop day 1
Incidence of postoperative nausea and vomiting
Time Frame: The day of surgery, postop day 1
Postoperative Nausea and vomiting: Incidence and severity recorded via patient report and use of antiemetic medication
The day of surgery, postop day 1
Neurological complications
Time Frame: The day of surgery, postop day 1 and at day 14 post-surgery. Patients that report or shows neurological complications at the post surgery visit day 14 will be followed up once more, 6 month after surgery.
Difference in frequency of neurological complications between groups: sensory deficits (paresthesia, numbness, hypoesthesia) and motor impairment (weakness, difficulty in muscular contraction) reported to and assessed by physiotherapist.
The day of surgery, postop day 1 and at day 14 post-surgery. Patients that report or shows neurological complications at the post surgery visit day 14 will be followed up once more, 6 month after surgery.
Length of Hospital Stay
Time Frame: 1-5 days post-surgery
Number of postoperative days in hospital.
1-5 days post-surgery
Difference in postoperative pain depending on method of anesthesia
Time Frame: The day of surgery, postop day 1 and 14 days post-surgery
Exploratory analysis by anesthesia type: Comparison of pain scores (assessed by NRS (0-10)) and opioid consumption (equivalents in mg) between patients receiving general anesthesia versus spinal anesthesia
The day of surgery, postop day 1 and 14 days post-surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Region Skane

Collaborators

Greta and Johan Kock Foundation

Investigators

  • Principal Investigator: Andreas Ekman, MD, PhD, VO Planned Operations, Trelleborg Hospital, and Lund University, Sweden

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 5, 2026

Primary Completion (Estimated)

March 1, 2027

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

December 22, 2025

First Submitted That Met QC Criteria

January 13, 2026

First Posted (Actual)

January 20, 2026

Study Record Updates

Last Update Posted (Actual)

May 8, 2026

Last Update Submitted That Met QC Criteria

May 4, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025-06626-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will be de-identified; each patient receives a unique enrollment number. De-identified study data will be stored in an Excel spreadsheet secured behind Lund University's institutional firewall. Data will not be shared publicly. Access to anonymized datasets may be considered upon reasonable request to the principal investigators, subject to GDPR compliance and institutional review approval.

Data Availability: Results and findings will be published in peer-reviewed journals and may be presented at scientific conferences. Individual patient data will remain confidential and protected in accordance with applicable data protection regulations.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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