This prospective, randomized, controlled clinical trial aims to evaluate the effectiveness of nephrostomy tract local anesthetic infiltration for postoperative pain control in patients undergoing prone percutaneous nephrolithotomy. Eligible patients will be randomly assigned to either a control group receiving standard systemic postoperative analgesia or an intervention group receiving standard analgesia plus infiltration of 20 mL of 0.25% bupivacaine along the nephrostomy tract at the end of surgery. Postoperative pain will be assessed using the Visual Analog Scale at 1, 6, 12, and 24 hours. Secondary outcomes will include time to first analgesic requirement, total opioid consumption during the first 24 hours, need for rescue analgesia, time to mobilization, length of hospital stay, and treatment-related complications. The study is designed to determine whether nephrostomy tract infiltration provides a simple, safe, and effective adjunct for reducing pain and analgesic consumption after percutaneous nephrolithotomy.