(D.C. United) (D.C. United)

D.C. United defender Jeff Parke, sidelined for weeks with migraines and vertigo, underwent inner ear surgery at Georgetown Hospital on Wednesday. A timetable to return remains uncertain.

The veteran center back started the first 13 matches before being sidelined by a foot injury. While out, Parke began experiencing head issues. The team administered standard concussion protocol. Several specialists examined him. Two weeks ago, United officials said one doctor had ruled out an inner-ear tear.

Parke’s outpatient procedure on his left ear this week was to address perilymph fistula, which, according to the American Hearing Research Foundation, is an “abnormal opening between the air-filled middle ear and the fluid-filled inner ear.”

Head trauma is the most common cause, the foundation says, and usually involves a direct blow to the ear.

“We are pleased that Jeff has undergone successful surgery on his inner ear and we are hopeful that he is able to return to full participation in the near future,” United General Manager Dave Kasper said in a written statement.

Rookie Steve Birnbaum, the second overall draft pick, has started in Parke’s place and, until recently, has performed well partnering with captain Bobby Boswell. For depth, United acquired Kofi Opare from the Los Angeles Galaxy two weeks ago.