Can a single injection before stitches cut Post-Surgery opioid use?

This trial tests whether injecting a mixture of local anesthetics and pain relievers under the skin before closing the wound can reduce pain after orthopedic wide excision surgery for bone or soft tissue tumors. Half of the participants will receive the active mixture, while the other half will get a saline control, and neither they nor the assessors will know which. The main goal is to see if this injection lowers the amount of opioid pain medication needed in the first 24 hours after surgery, with additional measures of pain scores, nausea, and quality of recovery.