San Francisco Chronicle Quotes Dr. Kenneth Jung: How is 49ers’ Fred Warner playing with a fractured ankle? A surgeon explains

Fred Warner isn’t playing as well as he was to start the season, but plenty of fans might be wondering: How is he still even playing?

The San Francisco 49ers’ All-Pro linebacker revealed last week that he suffered a broken bone in his ankle two months ago and has since taken pregame painkilling shots that have allowed him to not miss a game. So how has been able to stay on the field with such an injury?

Dr. Kenneth Jung, a foot and ankle surgeon who is a consultant to the Los Angeles Rams, said it’s likely Warner has an avulsion fracture, which occurs when a small piece of bone attached to a tendon or ligament is pulled away from the main part of the bone. The bone fragment and main bone are typically close enough to fuse together naturally. In that case, the fracture is considered stable, surgery isn’t required, and effective pain management can allow an athlete to play.

“When you sprain something, obviously things are getting twisted,” said Jung, who works at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles. “So, the ligament is under stress or strain, and it can pull off a piece of bone. Technically, the bone is broken, but it’s not like a fracture where the bone gets twisted and it snaps in half, or something similar to that. Some of that is semantics. But when someone says, ‘I have a fracture’ — not all fractures are the same.”

“With these avulsion fractures, if you are continually putting stress on the bone, it may not heal.” Jung said. “You expect with time with a sprain or small fracture that it tends to improve, but it’s very possible that he keeps re-aggravating it. That can cause persistent pain, and persistent pain can obviously affect his performance.”