Can a simple steroid shot unlock stiff knees after surgery?

This study is testing if giving a common steroid (hydrocortisone) through an IV after knee replacement surgery helps patients regain better knee movement and feel less pain. It involves 132 adults getting a single knee replacement who will receive either the steroid or a placebo (saltwater) shot at three times after surgery. Researchers will track how well patients can bend their knee, their pain levels, and their need for pain medication for up to two years to see if the steroid provides lasting benefits.