I don't know about taking these two together for an injury, but I've always taken these two together for anti-aging benefits:

I read a study which said that Acetyl-L-carnitine and alpha lipoic acid have been shown to reduce damage to mitochondria, the part of a cell which produces energy and is thought to be compromised in aging - some research findings published in the US journal, Proceedings of the National Academy of Science (PNAS), in 2002 describes how aged rats were given oral acetyl-L-carnitine and lipoic acid. As well as reducing mitochondrial aging in the rats’ brains, the supplementation reversed the already present signs of aging.

At the moment I'm taking an Acetyl L Carnitine & Alpha Lipoic Acid supplement made by Metabolics Ltd - they've already put the two together in one supplement which is really handy, so you don't have to worry about getting the balance of each ingredient right.