Comparison of Analgesic Effect of Adductor Canal Block, IPACK, and Genicular Nerve Block Following Total Knee Arthroplasty Under Spinal Anesthesia

Total knee arthroplasty (TKA) is a surgical procedure performed on patients with severe pain and severely limited range of motion in the knee joint due to knee osteoarthritis, when traditional conservative treatments have failed. Fifty-eight percent of patients who undergo TKA experience moderate or severe pain in the postoperative period. Inadequate pain control leads to complications such as venous thrombosis, coronary ischemia, myocardial infarction, and pneumonia, and increases morbidity. In addition, failure to control postoperative pain negatively affects physical therapy procedures. This situation prolongs the rehabilitation and hospital stay of patients, thus increasing care costs. Therefore, it is of great importance to reduce the patient's pain after TKA.

Femoral nerve block (FNB) has traditionally been a critical component of multimodal analgesia in TKA due to its high analgesic efficacy. However, FNB limits physical therapy by causing motor limitations in the quadriceps muscle. This situation causes delays in ambulation and discharge. Due to the difficulties in rehabilitation observed in patients undergoing FNB due to quadriceps muscle weakness, different techniques were sought and the Adductor canal block (ACB) emerged. AKB is a sensory block that blocks the saphenous nerve, a sensory nerve that courses in the adductor canal in the thigh, thus preserving motor function. It is an alternative block to FNB by providing adequate analgesia to the anterior compartment of the knee.

Genicular nerves include branches of the femoral, common peroneal, saphenous, tibial and obturator nerves that innervate the knee capsule. It is known that the superolateral, superomedial and inferomedial branches of the genicular nerve are close to the periosteum of the tibia and femur and play a role in sensory innervation of the anterior part of the knee joint. Genicular nerve block (GNB) is used in chronic osteoarthritis pain and has been used in recent years to relieve postoperative pain in TKA.

Infiltration between Popliteal Artery and Capsule of the Knee (IPACK block) is performed by infiltrating local anesthetic (LA) between the popliteal artery and the knee capsule under USG guidance. The sciatic nerve has an important function in the motor and sensory innervation of the posterior leg. In the IPACK block application, the LA spreads along the popliteal fossa and proximal sciatic nerve involvement does not occur. Thus, the sensory nerve network innervating the posterior part of the knee is blocked. Since IPACK block provides only sensory block without causing motor block, it is a new method recommended for analgesia in knee surgery as an alternative to sciatic nerve block, which causes motor block.

Method: