Efficacy of Genicular Block on Total Knee Arthroplasty Surgery

Patients scheduled for elective primary unilateral total knee arthroplasty were randomly allocated in a 1:1 ratio to the genicular nerve block (GNB) group or the placebo control group.

Approximately 30 minutes before surgery, all patients underwent an ultrasound-guided injection procedure targeting the superomedial, superolateral, and inferomedial genicular nerves.

Patients in the GNB group received 5 mL of 0.25% bupivacaine at each target (total volume: 15 mL). Patients in the placebo control group received 5 mL of 0.9% normal saline at each corresponding target (total volume: 15 mL).

The injections were performed by an anesthesiologist who was aware of group allocation and was not involved in postoperative outcome assessment. Participants and outcome assessors remained blinded to treatment allocation.

All patients received standardized general anesthesia and postoperative multimodal analgesia, including intravenous paracetamol, intramuscular diclofenac, and patient-controlled intravenous morphine analgesia.

Postoperative pain intensity was assessed using the visual analog scale (VAS) at rest and during movement. The primary outcome was movement-evoked VAS at 24 hours after surgery. Secondary outcomes included other postoperative VAS measurements, morphine consumption, and knee range of motion.

• Genicular blocks (bupivakain) (Drug): Patients received preoperative ultrasound-guided genicular nerve block with 5 mL of 0.25% bupivacaine injected at each of three anatomical targets: superomedial, superolateral, and inferomedial genicular nerves (total volume: 15 mL).
• placebo injection with 0.9% sodium chloride (Drug): Patients received preoperative ultrasound-guided placebo injections consisting of 5 mL of 0.9% normal saline at each of the same three genicular nerve targets (total volume: 15 mL).
• Paracetamol (acetaminophen)+diclofenac (Drug): Standardized postoperative multimodal analgesia consisting of intravenous paracetamol 1 g every 8 hours and intramuscular diclofenac sodium 75 mg every 12 hours during the first 48 postoperative hours, administered to both study groups.
• Patient Control Analgesia (PCA) Morphine (Drug): Postoperative intravenous patient-controlled analgesia with morphine, programmed to deliver a 1 mg demand dose with a 15-minute lockout interval. The same PCA regimen was used in both study groups.

Primary outcomes

• Visual Analog Scale Measure [0-48 hours]: VAS scores are assessed at 0th, 24th and 48th hours post operatively VAS score consists of 0-10 in numbers, the bigger the number the worse the pain

Secondary outcomes

• opioid consumption [0-48 hours]: Morphine consumption is assesed by PCA
• Range of Motion Measurements [0-48 hours]: Knee range of motion (ROM) are assessed in degrees during active knee flexion. Measurements are obtained preoperatively and at predefined postoperative time points. Higher values indicate greater knee flexion.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Scheduled for unilateral and primary total knee arthroplasty
* Older than 18 years of age

Exclusion Criteria:

* Younger than 18 years
* Bilateral knee arthroplasty
* Revision case of knee arthroplasty

• Mustafa Azizoglu, Associated Professor, Principal investigator, Mersin university Faculty of Medicine, Department of Anesthesiology and Reanimation