I don't recall seeing any official medical release or something like that.
I do remember a piece that quoted the family as saying he did indeed have the fracture. But the claim that the family said that may not be verifiable.
If there was the fracture, it might be a strategical move to hold it back until the official investigation is complete.
The fact that Wilson was taken to the hospital indicates there was an injury. Its also important to note that there was nothing official from the hospital on George Zimmerman’s injury for nearly 4 months.