Total hip and knee joint replacements are among the most common and painful orthopedic procedures performed worldwide, often requiring intensive analgesia to support early ambulation and recovery. Despite widespread use of multimodal regimens, many patients still rely on opioids, which can cause sedation, nausea, constipation, and long-term dependency. Evaluating Suzetrigine in this high-need population may improve recovery trajectories, reduce opioid consumption, and support enhanced recovery protocols. Given the growing surgical volume and the emphasis on opioid-sparing strategies, rigorous investigation of Suzetrigine's efficacy in joint replacement is of high clinical value. In this study, patients undergoing primary total hip replacement will be randomized to receive either Suzetrigine or placebo for seven days, with the loading dose administered prior to surgery. The primary outcome is cumulative 48-hour opioid consumption in oral morphine equivalents starting from entry into the post-anesthesia care unit (PACU).