Total Knee Arthroplasty patients are among the orthopedic cases that experience severe postoperative pain. In these cases, pain must be controlled. If pain is not controlled, early mobilization cannot be achieved. This can result in delayed physical therapy, prolonged hospital stays, the development of nosocomial infections, and impaired cognitive function. All of these factors contribute to increased patient care costs. Multimodal analgesia methods are used to control this pain. One of these methods is peripheral nerve blocks. Peripheral nerve blocks provide pain control and reduce the likelihood of opioid use and related side effects such as nausea, vomiting, and constipation. Current studies recommend Adductor Canal Blocks and iPACK (space between the popliteal artery and the posterior knee capsule) blocks for Total Knee Arthroplasty patients. In addition, studies are also being conducted on the application of the Suprainguinal Fascia-Iliaca Block in Total Knee Arthroplasty patients. The differences in postoperative analgesic effects between these methods are a matter of interest. No study has been conducted comparing the effects of these two approaches, which are routinely applied in our clinic and comply with guidelines, on the postoperative stress response. Regional anesthesia provides adequate pain control and has a positive effect on the stress response. The investigators aim to see a similar effect in peripheral nerve blocks. Therefore, comparing the methods that mentioned will contribute to the literature. In this study, the effects of these two different approaches on postoperative stress response and analgesic efficacy will be compared in terms of patients' postoperative opioid consumption, pain at rest and with movement, time to first analgesic need and development of motor block. IL-6 and CRP values will be examined pre-operatively and post-operatively to measure the effects on the stress response.