Comparison of Spinal Anesthesia With Intrathecal Morphine Versus PENG Block With or Without Dexamethasone in Hip Arthroplasty

The goal of this clinical trial is to learn which of three regional anesthesia approaches provides better pain relief and safety for older adults having planned hip replacement surgery. Researchers will study people aged 60 years and older who are scheduled for elective total hip arthroplasty. The main questions this study aims to answer are: Which anesthesia method provides better pain control after surgery? Which method reduces the need for opioid pain medicines? Are there differences in side effects and recovery between the approaches? Participants will be randomly assigned to one of three groups. All participants will receive spinal anesthesia. One group will receive spinal anesthesia with intrathecal morphine. The other two groups will receive spinal anesthesia combined with a nerve block called the pericapsular nerve group (PENG) block, with or without the addition of dexamethasone. Participants will have their pain levels measured at regular times during the first two days after surgery. Researchers will also record opioid use, time to first pain medication, ability to move after surgery, length of hospital stay, and any side effects such as nausea or itching. Blood tests will be used to measure markers of inflammation. The results of this study may help doctors choose safer and more effective pain control strategies for people undergoing hip replacement surgery.

Inclusion Criteria: * Adults aged 60 to 100 years * Scheduled for elective total hip arthroplasty * American Society of Anesthesiologists (ASA) physical status I-III * Ability to understand the study procedures and provide written informed consent Exclusion Criteria: * Known allergy or hypersensitivity to ropivacaine, morphine, or dexamethasone * Coagulation disorders or ongoing anticoagulant therapy contraindicating spinal anesthesia or regional nerve blocks * Infection at the site of spinal or peripheral nerve block injection * Pre-existing neurological disorders affecting sensory or motor function * Severe hepatic or renal insufficiency * Chronic opioid use for more than 3 months prior to surgery * Refusal or inability to provide informed consent