This study will prospectively compare the preventive effect of liposomal bupivacaine combined with plain bupivacaine versus plain bupivacaine alone on rebound pain after nerve block in patients undergoing orthopedic extremity surgery. The primary aim is to assess whether the combination reduces the incidence or severity of rebound pain (i.e., more effectively covers the postoperative inflammatory peak on days 2-3 and provides a smoother regression curve of sensory blockade). Secondary aims include evaluation of upper limb functional scores, occurrence of chronic pain, and health-related quality of life. All aims will be assessed over 72 hours or the duration of hospitalization if shorter.
18-65 years old;
ASA Physical Status 1-3;
Scheduled for elective unilateral orthopedic surgery of the upper or lower extremity.
Women who are pregnant or breastfeeding;
Bupivacaine sensitivity or known allergy;
Contraindication for nerve blocks;
Enrollment in another clinical trial that could confound pain evaluation;