This study is looking at two drugs, **EXPAREL** and **bupivacaine**, to help manage pain after ankle surgery. EXPAREL is a long-acting pain medication that comes in a single dose and is designed to provide pain relief for a longer time than regular bupivacaine. Bupivacaine is a local anesthetic that provides temporary pain relief. The study will compare how well each drug works in managing pain, how much opioid medication is needed afterward, and how satisfied patients are with their pain management. **Key Points:** - The study involves a single dose of the medication and will track pain relief and drug consumption for up to 96 hours. - Participation requires undergoing ankle replacement surgery and meeting specific health criteria. - This is a randomized, double-blind study, meaning neither you nor the doctors will know which drug you receive. To take part, you must be between 18-40 years old, have a specific health status, and be able to follow the study schedule. You cannot participate if you have certain medical issues or a history of drug abuse. The study aims to find better ways to manage pain with fewer side effects from opioid drugs.