GENicular Nerve Block in KNEE Arthroplasty

Helse Møre og Romsdal HF70 enrolled

Overview

The goal of this clinical trial is to learn whether a preoperative genicular nerve block (GNB) can reduce pain after knee replacement surgery in adults with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). It will also assess whether this treatment can reduce opioid use and improve recovery. The main questions it aims to answer are: * Does a preoperative GNB reduce pain during movement 24 hours after surgery compared with placebo? * Does it reduce opioid consumption and improve physical activity and functional outcomes after surgery? Researchers will compare patients receiving a GNB to patients receiving a placebo injection to see if the nerve block improves postoperative pain and recovery. Participants will: * Be randomly assigned to receive either a GNB or a placebo injection before surgery * Undergo standard knee replacement surgery and postoperative care * Report pain levels at regular intervals after surgery * Complete questionnaires on function, quality of life, and recovery * Wear an activity monitor to measure physical activity after surgery * Attend follow-up assessments at 1 week, 1 month, and 3 months

Knee osteoarthritis (OA) is a common condition that causes pain, stiffness, and reduced mobility. For many patients, total knee arthroplasty (TKA) is an effective treatment to relieve pain and improve function. However, managing pain after surgery remains a major challenge. Poorly controlled pain can delay recovery, reduce mobility, and increase the need for opioid medications, which may have unwanted side effects. This study investigates whether a specific pain treatment called a genicular nerve block (GNB) can improve pain control after knee replacement surgery. A GNB is a minimally invasive procedure where a local anesthetic is injected around small sensory nerves that supply the knee. While this technique is already used to treat chronic knee pain, its effect when given before surgery is not well established. In this randomized, placebo-controlled clinical trial, patients undergoing primary TKA surgery will be assigned to receive either a GNB or a placebo injection before the operation. Neither the patients nor the healthcare providers involved in their care will know which treatment is given, ensuring unbiased results. The main goal of the study is to determine whether patients who receive the nerve block experience less pain during movement in the first 24 hours after surgery compared with those who receive placebo. In addition, the study will evaluate whether the nerve block reduces the need for opioid pain medications, improves early physical activity, and leads to better recovery and function in the weeks and months after surgery. Participants will be followed for three months after surgery. During this period, they will report pain levels, complete questionnaires about their function and quality of life, and wear an activity monitor to measure movement and recovery. The study will also assess possible side effects and complications, as well as the cost-effectiveness of the treatment. By improving pain management and recovery after TKA, this study aims to contribute to better patient outcomes and more effective use of healthcare resources.

Interventions

Preoperative genicular nerve block (GNB)PROCEDURE

Participants randomized to the intervention group will receive a preoperative ultrasound-guided genicular nerve block prior to surgery. The procedure is performed under sterile conditions by an experienced anesthesiologist using ultrasound guidance to identify anatomical landmarks. A local anesthetic (ropivacaine 5 mg/mL) is injected at three sites targeting the sensory innervation of the knee joint: the superolateral, superomedial, and inferomedial genicular nerves. A volume of 5 mL is administered at each site, for a total of 15 mL. If the accompanying genicular artery is not visualized, the injection is performed at the corresponding bony landmark. The intervention is administered once before surgery in addition to standard perioperative care, including spinal anesthesia, multimodal analgesia, and local infiltration analgesia during surgery.

Placebo nerve blockPROCEDURE

Participants randomized to the placebo group will receive a preoperative ultrasound-guided placebo nerve block prior to surgery. The procedure is performed under sterile conditions by an experienced anesthesiologist using ultrasound guidance to identify anatomical landmarks. 5 mL of 0.9% normal saline is injected at three sites targeting the sensory innervation of the knee joint: the superolateral, superomedial, and inferomedial genicular nerves. A volume of 5 mL is administered at each site, for a total of 15 mL. If the accompanying genicular artery is not visualized, the injection is performed at the corresponding bony landmark. The intervention is administered once before surgery in addition to standard perioperative care.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Symptomatic knee OA grade II-IV according to the Kellgren-Lawrence classification system scheduled for primary total knee arthroplasty * American Society of Anesthesiologists (ASA) Physical Status grade I-III * Able to provide written informed consent * Able to undergo surgery under spinal anesthesia Exclusion Criteria: * Younger than 18 or older than 80 years * ASA physical status IV * Allergy to local anesthetics * Revision surgery * Chronic opioid use (\> 3 months) * Coagulopathy * Cognitive impairment * Inability to comply with study procedures * Patients scheduled for day care surgery.

Outcomes

Primary Outcomes

Nummerical rating scale (NRS) pain

Pain during ambulation measured using an 11-point NRS (0-10); reported as the difference in mean scores between the GNB and placebo groups.

Time frame: 24 hours

Secondary Outcomes

NRS Pain

Pain during ambulation measured using an 11-point NRS (0-10) at predefined postoperative time points; reported as the difference in mean scores between the GNB and placebo groups.

Time frame: 1 week, 1 month and 3 months

Cumulative opioid consumption

Self-reported oral opioid consumption collected via telephone or digital questionnaire and converted to cumulative oral morphine equivalents (MED) using standard conversion factors.

Time frame: 3 months

EQ-5D-5L

A generic patient reported outcome measure measuring quality of life. The scale ranges from 100 ('the best imaginable health state') to 0 ('the worst imaginable health state' ).

Time frame: 3 months

Steps per day

ActivPAL4Pro accelerator registration of mean steps per day measured 24/7 for a week.

Time frame: 1 week and 3 months

Forgotten Joint Score (FJS)

FJS is a 12 item scale assessing the ability to forget the operated joint as artificial during activities of daily living. Ranges from 0 (bad) to 100 (excellent)