Comparison between ultrasound guided modified 4 in 1 block with combined adductor canal and Injection between Popliteal Artery and Capsule of the Knee (IPACK) for postoperative analgesia in Total knee arthroplasty

Total knee arthroplasty or replacement (TKA), arthroscopic knee surgeries are one of the most commonly performed, life-changing surgical procedures, leading to improved health-related quality of life and functional status, therefore these surgeries demand better outcomes with minimal morbidity and mortality and early mobilization and discharge. The central neuraxial blocks were associated with higher complications, morbidity and delayed ambulation. The regional techniques provide a better and early outcome as compared to the central neuraxial techniques.Regional analgesia (RA) is an important component of multimodal analgesia to deal with perioperative pain. Regional anaesthesia includes epidural analgesia, femoral n. block, adductor canal block, sciatic n. block, IPACK, etc.But these blocks have many drawbacks. Femoral n. block is associated with quadriceps muscle weakness leading to delay in patient’s mobility. Sciatic n. block also causes foot drop. The Adductor canal block does not cover the skin on the back of the knee.Surgeons refuse IPACK because of diffusion of local anaesthetics disturbs the anatomy of the surgical field. 70 Patients between the age group of 45 to 75 years old of either sex belonging to ASA I, II, III will included in the study. Using computer generated randomization, patients will be allotted in to two groups of 35 each. One group will receive the newly developed regional technique Modified 4 in 1 with the addition of USG and PNS guided Vastus medialis nerve block. The patients in this block will receive 20ml injection bupivacaine 0.25% and 2ml of injection dexamethasone 8mg added as adjuvant (total volume of drug 22 ml). The second group will receive the ACB and IPACK block. ACB is as effective as FNB in providing postoperative analgesia after knee surgery and ACB carries the advantage of preserving or minimally affecting quadriceps strength thereby facilitating early ambulation and postoperative rehabilitation. A new regional analgesia technique known as IPACK (infiltration between popliteal artery and capsule of the knee) has been used in practice since 2014. In this technique the superomedial and lateral genicular nerves,branches of the sciatic nerve and articular branches of the obturator nerve in the popliteal region are blocked providing analgesia to the posterior capsule of the knee joint, without affecting motor function of the limb. Patients in this group will receive ultrasound guided Adductor canal block and IPACK block with 12ml and 10ml respectively of 20ml injection bupivacaine 0.25% and 2ml of injection dexamethasone 8mg added as adjuvant respectively (total volume of drug 22 ml). The patient’s vitals, VAS score, total analgesic consumption, quadriceps muscle strength will be noted at regular intervals for 48 hours post operatively and the data will be compiled and sent for statistical analysis.