Bone-Injected morphine tested for knee surgery pain

This study tested whether adding the pain medication morphine to a standard antibiotic injection directly into the bone during knee replacement surgery helps reduce pain after the operation. About 100 patients having their first knee replacement were randomly assigned to receive either the antibiotic with morphine or the antibiotic with a placebo (inactive substance) injected into their shin bone. Researchers then measured patients' pain levels and how much additional pain medication they needed after surgery to see if the bone injection made a difference.