Outcomes data. Many surgical treatments have published results regarding outcome, patient satisfaction, complication rate, etc. Your surgeon should be able to provide specific data, not only about published data, but also their personal outcomes. Ask how many specific procedures have they performed, and do they have specialized training. Finally, go get a 2nd opinion and cross-reference your answers. Good luck!
There are too many- -procedures & treatments in orthopedics that you should Google a specific surgical procedure or disease process treated by orthopedic surgeons. You will find reams of paper to read. It takes 4-6 years to become an orthopedic surg. After medical school, so there is a lot to cover. .