GENicular Nerve Block in KNEE Arthroplasty

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.

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.