Genicular Nerve Blocks for Anterior Cruciate Ligament Knee Surgery

Genicular Nerve Blocks for Arthroscopic Anterior Cruciate Knee Surgery: a Randomized Controlled Trial

The purpose of this randomized controlled trial is to assess a new analgesia regimen that includes the addition of genicular never blocks to our current standard regimen of peripheral nerve blocks, which includes an adductor canal block (ACB) and interspace between the popliteal artery and capsule of the posterior knee block (IPACK). The main questions it aims to answer are:

1. Does addition of genicular nerve blocks to standard peripheral block regimen significantly reduce the mean opioid consumption by 33% in the first 24 hours?
2. Does genicular nerve blocks reduce NRS pain scores?
3. Does genicular nerve blocks facilitate earlier discharge?
4. Does genicular nerve blocks last longer than 24 hours?
5. Does genicular nerve blocks improve pain management?

Eligible patients are those undergoing an anterior cruciate ligament repair at the Hospital for Special Surgery and participants will be randomized to receive the intervention (genicular nerve block) or the standard of care.

Genicular nerve blocks have been shown to provide effective analgesia for chronic osteoarthritis knee pain. There are several publications supporting its use for chronic knee pain but there is a scarcity of literature in its use in the perioperative period. Recently, it has been shown to provide effective analgesia for total knee arthroplasty. This will be a novel application for it to be used for anterior cruciate ligament surgery. There are only a couple of prospective and retrospective studies that showed promising analgesic benefits for anterior cruciate ligament repairs. There are currently no randomized controlled trials published investigating the use of genicular nerve blocks for anterior cruciate ligament surgery.

Researching novel innovative motor-sparing and opioid-sparing peripheral nerve blocks for have been the focus of research. Studies have investigated the motor sparing benefits of the adductor canal block, the effective analgesic benefits of the IPACK block, the phrenic sparing benefits of the superior trunk block, and the analgesic benefits of the pericapsular nerve group block and lateral femoral cutaneous nerve. Genicular nerve blocks would be a potential additive block that may further enhance the recovery of patients undergoing knee surgeries, including unicondylar, total knee and anterior cruciate ligament repair patients.

Inclusion Criteria:

• Age 18 - 80
• English speaking
• American Society of Anesthesiologists (ASA) I - III
• BMI < 35
• Scheduled for ambulatory arthroscopic unilateral anterior cruciate ligament repair surgery with bone tendon bone autograft

Exclusion Criteria:

• History of chronic pain syndromes
• Chronic opioid use (daily morphine milligram equivalents > 30 mg for at least 3 months)
• Contraindication to peripheral nerve blocks
• Contraindication to neuraxial anesthesia
• History of peripheral neuropathy or pre-existing neurological deficits
• Psychiatric or cognitive disorder that prohibit patient from following study protocol
• Allergy to local anesthetic or study medications
• Multi-ligament surgery
• History of substance abuse
• Infection at the site of injection
• diagnoses of Type I or Type II diabetes