It is incorrect to call post-traumatic stress an injury; it is often the result of an injury, but it's the reaction to the injury or traumatic event that is disordered. Two people can experience the exact same traumatic event, even the same kind of injury, and react to it very differently. That's why it's correct to call PTSD a "disorder." Most people react to an injury or a traumatic event in a normal, expected pattern of grief or loss that they can work through in a normal, expected period of time with the normal, expected treatments. And then some people react to the same traumatic event in a disordered way that does not follow the regular, normal, expected patterns, that disrupts their ability to function in the normal, expected ways, and for which treatment in the normal, expected ways does not work.
I think rather than removing the word "disorder" from PTSD, we should be working to remove the stigma of the disorder from our society. PTSD is not, and should not be, a life-long burden. It's a treatable condition, and we should be getting our veterans the mental health support they need, the medication they need, so that they can move on from PTSD and live a disorder-free life.
70% of the U.S. population now lives in a state where same-sex marriage is legal. At 36 and counting!