The German had Barker on the canvas twice before the referee brought a halt to the fight after the towel was thrown in, with the Londoner clearly struggling.
Trainer Tony Sims revealed that his fighter had suffered the dislocation early on in the first and claimed that Barker may now contemplate retirement.
The Daily Mail quotes Sims as saying: "His hip went in the first round when he threw a right hand. In the second round he got clipped with a shot and it's completely gone on him.
"I was hoping it would be a muscle injury but when he went down the second time, I threw the towel in because he couldn't move.
"It's a disaster and I don't think you'll see him in the ring again."
Sturm reportedly offered Barker a rematch for the IBF middleweight title on home soil following the fight.