Peripheral Nerve Blocks and Postoperative Pain and Mobilization After Total Knee Arthroplasty

March 2, 2026 updated by: Guldeniz Argun, Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital

Comparison of the Effects of Peripheral Nerve Blocks Applied in Total Knee Arthroplasty on Pain Control and Mobilization: A Prospective Observational Study

Total knee arthroplasty (TKA) is frequently associated with significant postoperative pain, which may delay early mobilization and negatively affect functional recovery. Peripheral nerve blocks are widely used as part of multimodal analgesia strategies to improve postoperative pain control while minimizing opioid consumption and preserving motor function. Different peripheral nerve block techniques may result in varying analgesic efficacy and mobilization outcomes.

The aim of this prospective observational study is to compare the effects of commonly used peripheral nerve block techniques on postoperative pain control and early mobilization in patients undergoing total knee arthroplasty under spinal anesthesia. Patients receiving fascia iliaca plane block are compared with those receiving a combination of adductor canal block and interspace between the popliteal artery and capsule of the knee (IPACK) block.

The primary outcome is postoperative opioid consumption within the first 24 hours after surgery. Secondary outcomes include postoperative pain scores assessed at predefined time intervals, early mobilization parameters, and opioid-related adverse effects. The findings of this study are intended to contribute to optimizing analgesic strategies and improving early functional recovery following total knee arthroplasty.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Total knee arthroplasty (TKA) is a commonly performed orthopedic procedure associated with moderate to severe postoperative pain that may impair early mobilization and delay rehabilitation. Effective postoperative analgesia is essential to facilitate early functional recovery, reduce opioid consumption, and minimize postoperative complications. Multimodal analgesia strategies incorporating peripheral nerve blocks have become increasingly important in postoperative pain management following TKA.

Peripheral nerve block techniques aim to provide effective analgesia while preserving motor function to support early ambulation. Traditional proximal blocks may provide adequate pain relief but can be associated with motor weakness that limits mobilization. More distal techniques, such as the adductor canal block, are increasingly preferred due to their motor-sparing characteristics. The interspace between the popliteal artery and capsule of the knee (IPACK) block has been introduced to improve posterior knee analgesia without affecting motor function. The fascia iliaca plane block represents another commonly used regional anesthesia technique; however, comparative clinical data regarding analgesic efficacy and mobilization outcomes between these approaches remain limited.

This prospective observational study is conducted in patients undergoing unilateral total knee arthroplasty under spinal anesthesia. Participants receive either fascia iliaca plane block or a combination of adductor canal block and IPACK block as part of routine clinical practice. The study evaluates postoperative outcomes during the first 24 hours following surgery.

The primary objective is to compare total opioid consumption within the first 24 postoperative hours between the two peripheral nerve block techniques. Secondary objectives include assessment of postoperative pain intensity using the Numeric Rating Scale (NRS) at predefined time points, evaluation of early mobilization parameters, and comparison of opioid-related adverse effects.

Pain assessments are performed at 0, 2, 6, 12, and 24 hours postoperatively. Early mobilization is evaluated using standardized functional assessments, including walking ability and motor function tests of quadriceps and ankle dorsiflexor muscles. All patients receive standardized spinal anesthesia and postoperative patient-controlled analgesia to ensure comparable perioperative management.

The results of this study are expected to provide clinical evidence regarding the comparative effectiveness of commonly used peripheral nerve block techniques and to support optimization of postoperative analgesia protocols aimed at improving recovery after total knee arthroplasty.

Study Type

Observational

Enrollment (Actual)

90

Contacts and Locations

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

Study Locations

  • Turkey (Türkiye)
      • Ankara, Turkey (Türkiye), 06200
        • SBU Abdurrahman Yurtaslan Ankara Oncology Training and Research 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

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adult patients undergoing elective unilateral total knee arthroplasty at a tertiary care hospital. Eligible participants include patients receiving spinal anesthesia and perioperative peripheral nerve block analgesia as part of routine clinical practice. The population represents individuals undergoing primary knee replacement surgery for degenerative joint disease who are suitable for early postoperative mobilization and standardized postoperative pain management protocols.

Description

Inclusion Criteria:

  • Adult patients aged 18-80 years
  • Scheduled for elective unilateral total knee arthroplasty
  • Surgery performed under spinal anesthesia
  • American Society of Anesthesiologists (ASA) physical status I-III
  • Ability to understand the study procedures and provide informed consent

Exclusion Criteria:

  • Refusal to participate
  • Contraindications to spinal anesthesia or peripheral nerve block
  • Known allergy to local anesthetics
  • Chronic opioid use or opioid dependence
  • Preexisting neurological or neuromuscular disorders affecting lower extremities
  • Cognitive impairment preventing pain assessment
  • Infection at the injection site
  • Coagulopathy or ongoing anticoagulant therapy contraindicating regional anesthesia

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Fascia Iliaca Plane Block
Participants in this cohort receive an ultrasound-guided fascia iliaca plane block prior to surgery as part of routine perioperative analgesia. The block is performed under sterile conditions using an in-plane technique with a high-frequency linear ultrasound probe. A total volume of 40 mL of 0.25% bupivacaine is administered within the fascia iliaca compartment. All patients undergo spinal anesthesia for total knee arthroplasty and receive standardized postoperative patient-controlled analgesia.
Procedure: Fascia Iliaca Plane Block
Ultrasound-guided fascia iliaca plane block is performed under sterile conditions prior to surgery as part of perioperative analgesia. Using an in-plane technique with a high-frequency linear ultrasound probe, the needle is advanced beneath the fascia iliaca, and 40 mL of 0.25% bupivacaine is injected incrementally after negative aspiration to achieve spread within the fascia iliaca compartment.
Adductor Canal + IPACK Block
Participants in this cohort receive a combination of ultrasound-guided adductor canal block and interspace between the popliteal artery and capsule of the knee (IPACK) block prior to surgery as part of routine perioperative analgesia. The adductor canal block is performed with 20 mL of 0.25% bupivacaine, followed by an IPACK block using 20 mL of 0.25% bupivacaine under ultrasound guidance. All patients undergo spinal anesthesia for total knee arthroplasty and receive standardized postoperative patient-controlled analgesia.
Procedure: Adductor Canal Block + IPACK Block
An ultrasound-guided adductor canal block followed by an interspace between the popliteal artery and capsule of the knee (IPACK) block is performed prior to surgery as part of perioperative analgesia. The adductor canal block is administered using 20 mL of 0.25% bupivacaine injected adjacent to the femoral artery beneath the sartorius muscle. Subsequently, the IPACK block is performed with 20 mL of 0.25% bupivacaine injected into the tissue plane between the popliteal artery and the posterior capsule of the knee under ultrasound guidance.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total Postoperative Opioid Consumption
Time Frame: Within the first 24 hours after surgery
Total opioid consumption administered via patient-controlled analgesia (PCA) during the first 24 hours following total knee arthroplasty. Opioid use is recorded as the cumulative dose of morphine (mg) delivered by the PCA device.
Within the first 24 hours after surgery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Pain Intensity (NRS Score)
Time Frame: 0, 2, 6, 12, and 24 hours after surgery
Postoperative pain intensity assessed using the Numeric Rating Scale (NRS), where 0 indicates no pain and 10 indicates the worst imaginable pain. Pain scores are recorded at predefined postoperative time points under resting conditions.
0, 2, 6, 12, and 24 hours after surgery
Early Mobilization Performance
Time Frame: 24 hours after surgery
Early postoperative mobilization assessed using standardized functional evaluations, including walking ability, quadriceps muscle strength, and ankle dorsiflexor motor function scores recorded at postoperative assessment.
24 hours after surgery

Collaborators and Investigators

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

Sponsor

Dr Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital

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)

December 1, 2022

Primary Completion (Actual)

December 1, 2024

Study Completion (Actual)

January 15, 2025

Study Registration Dates

First Submitted

February 24, 2026

First Submitted That Met QC Criteria

February 24, 2026

First Posted (Actual)

March 2, 2026

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

March 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2022-11/2120

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data collected during this study will not be made publicly available. De-identified data may be shared upon reasonable request to the corresponding author, subject to institutional approval and applicable ethical and legal 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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