Evidence-based Review of Periarticular Injections and Peripheral Nerve Blocks in Total Knee Arthroplasty

Recently, post-operative pain management after Total Knee Arthroplasty (TKA) has focused on a multimodal approach for reducing opioid requirements, promoting early rehabilitation, and expediting discharge from hospital. Regional anesthesia, in the form of Periarticular Injections (PAI) and Peripheral Nerve Blocks (PNB), has shown promise as adjunctive therapy to oral analgesics.

To review the current literature surrounding regional anesthesia for TKA.

PNBs provide effective analgesia after TKA. Historically, femoral nerve blocks (FNB) have been commonly employed. FNBs, however, lead to the significant motor blockade to the quadriceps musculature, which can dampen early rehabilitation efforts and increase the risk of post-operative falls. Adductor Canal Blocks (ACB) have shown excellent results in reducing post-operative pain while minimizing motor blockade. Periarticular injections (PAI), and infiltration between the popliteal Artery and Capsule of the Knee (IPACK) have similarly helped in reducing patient discomfort after TKA and providing analgesia to the posterior capsular region of the knee.

PAIs, and PNBs are important elements in many multimodal postoperative pain management protocols after TKA. Current evidence appears to suggest that a combination of an ACB supplemented by posterior capsular analgesic coverage through PAI or IPACK may provide optimal results.