Dexamethasone vs Dexmedetomidine vs Combination as Adjuvants to Popliteal Sciatic Nerve Block in Children

Inclusion Criteria: * Children aged 3 to 12 years. * Scheduled for elective unilateral lower limb surgery (foot, ankle, or distal lower leg) under general anesthesia with a popliteal sciatic nerve block planned for postoperative analgesia. * ASA physical status I-III. * Ability of parents or legal guardians to understand the study procedures and provide written informed consent. * Child and parents/guardians available for telephone follow-up at 1 week and 1 month after surgery. Exclusion Criteria: * Refusal of the parents/legal guardians to provide informed consent or refusal of the child to cooperate with anesthesia or study procedures. * Known allergy or hypersensitivity to ropivacaine, dexamethasone, dexmedetomidine, or any component of the study medications. * Pre-existing neurological deficit or neuromuscular disease affecting the lower limbs (motor or sensory). * Coagulopathy or current therapeutic anticoagulation that contraindicates regional anesthesia. * Local infection, inflammation, or skin lesions at the planned block site. * Severe cardiac, hepatic, renal, or respiratory disease that, in the investigator's opinion, increases the risk of study participation. * History of clinically significant arrhythmias, severe bradycardia, or second/third degree atrioventricular block not treated with a pacemaker. * Developmental delay or severe cognitive impairment that precludes reliable pain assessment or follow-up. * Chronic use of opioid analgesics or sedatives (≥ 2 weeks of daily use before surgery). * Participation in another interventional clinical trial within the last 30 days. * Any other condition considered by the investigator to interfere with protocol adherence, safety monitoring, or reliable outcome assessment.