Effect of Rebound Pain on Chronic Postsurgical Pain After Total Knee Arthroplasty

This prospective observational study aims to evaluate whether rebound pain after peripheral nerve block is associated with the development of chronic postsurgical pain following elective total knee arthroplasty. Adult patients undergoing unilateral total knee arthroplasty under spinal anesthesia and receiving a peripheral nerve block as part of routine multimodal analgesia will be included. No additional intervention, drug administration, or biological sampling will be performed beyond standard clinical care. Rebound pain will be assessed during the early postoperative period using pain diaries, numeric rating scale pain scores, and analgesic consumption records. Chronic postsurgical pain and related outcomes will be evaluated at postoperative 3 and 6 months using validated instruments assessing pain severity, neuropathic pain features, psychological status, functional outcomes, and health-related quality of life. The primary outcome is the presence of chronic postsurgical pain at 3 months after surgery. Secondary outcomes include chronic pain at 6 months, pain intensity, neuropathic pain characteristics, opioid consumption, rescue analgesic requirements, sleep disturbance, and quality-of-life measures. The study also aims to explore demographic and clinical factors associated with rebound pain and chronic postsurgical pain.