A comparative study to evaluate the post-operative analgesic effect of IPACK Block and Intrathecal Buprenorphine in patients undergoing Arthroscopic Knee Surgeries under Spinal Anaesthesia

Pain in the immediate postoperative period after knee surgeries may hinder rehabilitative programmes and cause various pathophysiological consequences. Arthroscopic knee surgery is associated with variable amount of postoperative pain, which is caused by the irritation of the free nerve endings of the synovial tissue, anterior fat pad and joint capsule during surgical excision and resection. Several analgesic strategies such as systemic drugs, central or peripheral nerve blocks and intra-articular drug administration have been used to treat post-operative pain. Peripheral nerve blocks are ideally suited for lower limb surgeries because of the peripheral location of the surgical sites and potential to block pain pathways at multiple levels.

The recent technique of ultrasound guided local anaesthetic infiltration of the interspace between popliteal artery and the capsule of the posterior knee (IPACK) has shown promising results. The technique involves a very selective block of the terminal sensory branches of the posterior aspect of the knee without involvement of motor branches of the tibial nerves and peroneal nerves leading to reduced pain without motor weakness. Hence, preserving the sensory motor function of the leg and foot. This leads to earlier ambulation, rehabilitation and recovery in various knee surgeries.

In this study we aim to evaluate the postoperative analgesic effect of IPACK block vs Intrathecal Buprenorphine in patients undergoing arthroscopic surgeries under spinal anaesthesia. We hypothesize that IPACK block with spinal anaesthesia provides longer and better analgesia in the post-operative period, compared to Buprenorphine based spinal anaesthesia.