I'm going to have arthroscopic surgery on my ankle to remove some bone fragments from a football injury. How does the surgeon know where to stick the needle going in?

Ankle arthroscopy is on the rise. Surgeons use this method of diagnosing foot and ankle disorders more and more. Arthroscopy has made it much easier to "see" inside the joint. A long thin, needle with a tiny TV camera on the end is inserted through the skin into the joint. The surgeon sees what the camera sees displayed up on a video screen.

Surgery to remove bone fragments and other loose bodies is possible with this technique. Ankle replacement or fusion can be done arthroscopically. Many other ankle operations are performed using this method.

Usually there are two or three places where the needle can be inserted. The goal is to enter the joint without damaging the surrounding soft tissues. The surgeon must avoid piercing blood vessels or nerves. He or she must enter the joint without going too far and punching through the bone.

How this is done is determined using cadavers (bodies preserved after death for study). Anatomic studies of this type are used to find safe entrance called portals into the joint. Sometimes live patient studies are done.

Recently a new entry point has been discovered for the ankle. Surgeons from Gachon Medical School in Korea describe a posteromedial (PM) portal for ankle arthroscopy. They report the use of this PM portal to remove bone fragments in one case of a 29-year old man was safe and effective.