Osteoarthritis Clinical Trials

The goal of this clinical trial is to learn whether a preoperative genicular nerve block (GNB) can reduce pain after knee replacement surgery in adults with knee osteoarthritis (OA) undergoing total knee arthroplasty (TKA). It will also assess whether this treatment can reduce opioid use and improve recovery. The main questions it aims to answer are: * Does a preoperative GNB reduce pain during movement 24 hours after surgery compared with placebo? * Does it reduce opioid consumption and improve physical activity and functional outcomes after surgery? Researchers will compare patients receiving a GNB to patients receiving a placebo injection to see if the nerve block improves postoperative pain and recovery. Participants will: * Be randomly assigned to receive either a GNB or a placebo injection before surgery * Undergo standard knee replacement surgery and postoperative care * Report pain levels at regular intervals after surgery * Complete questionnaires on function, quality of life, and recovery * Wear an activity monitor to measure physical activity after surgery * Attend follow-up assessments at 1 week, 1 month, and 3 months