Genicular and Anterior Femoral Cutaneous Nerve Blocks for Total Knee Arthroplasty

Adductor canal nerve block (ACB), infiltration between the popliteal artery and the posterior knee capsule (IPACK), with or without peri-articular infiltration of local anesthetics (PAI), is the current standard of practice for analgesia coverage after total knee arthroplasty at the Hospital for Special Surgery. However, we frequently see patients with moderate post-operative knee pain, particularly on the anterior, middle, and lateral sides of the knee. There is limited clinical research on if adding a genicular nerve block could offer TKA patients a more complete analgesia. This study will test if the addition of genicular nerve block (including superolateral genicular nerve, superomedial genicular nerve, inferomedial genicular nerve, and nerve to vastus intermedius) and anterior femoral cutaneous nerve block could offer TKA patients a more complete analgesia. Participants will be randomly assigned to receive the genicular nerve block and anterior femoral cutaneous nerve block in addition to standard of care (intervention group), or not receive the nerve blocks (control group).

The main questions it aims to answer are:

• Does incorporating genicular nerve block and anterior femoral cutaneous nerve block to our current standard of care reduce patients' total opioid consumption in the first 24 hours after total knee arthroplasty (TKA) surgery?
• Does incorporating genicular nerve block and anterior femoral cutaneous nerve block to our current standard of care reduce patients' worst numeric rating scale (NRS) pain score in the post-anesthesia care unit (PACU)?
• Does incorporating genicular nerve block and anterior femoral cutaneous nerve block to our current standard of care result in earlier discharge from the post-anesthesia care unit (PACU)?
• Does incorporating genicular nerve block and anterior femoral cutaneous nerve block to our current standard of care reduce patients' total opioid consumption in the first 7 days after total knee arthroplasty (TKA) surgery?
• Does incorporating genicular nerve block and anterior femoral cutaneous nerve block to our current standard of care reduce patients' numerical rating scale (NRS) pain (both at rest and during movement) in the first 24 and 48 hours after surgery?

Participants will be randomly assigned to receive the genicular nerve block and anterior femoral cutaneous nerve block in addition to standard of care (intervention group), or not receive the nerve blocks (control group).

Comparing the intervention group to the control group, the researcher's primary outcomes are numerical pain in the post-anesthesia care unit and cumulative opioid consumption during the first 24 hours.

Inclusion criteria

• patients age 18-80
• patients undergoing ambulatory unilateral total knee arthroplasty, including 23 hour stay cohort
• ASA I-III
• BMI < 35

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
• Psychiatrics or cognitive disorder that prohibit patient from following study protocol
• allergy to local anesthetic or study medications
• multiligament surgery
• history of substance abuse
• infection at the site of injection
• chronic kidney disease
• currently taking anticonvulsants