Good call on going to an ortho vet. I did xrays on Tux a few years back and had a regular vet telling me he had severe HD and that I shouldn't be walking him for an hour at a time anymore. I asked for an ortho consult and the ortho vet said his hips weren't perfect but they were in darn good shape, and pretty much don't worry about it.
A friend of mine has an ACD who was diagnosed with a strained iliopsoas muscle earlier this year. She had a hard time getting it diagnosed, did the xrays and all. At one point her vet was so convinced it must be an ACL tear based on the limping that he wanted to go ahead and open her up for surgery. Luckily she got a second opinion, and started a rehab program with exercises and underwater treadmill. Her dog is doing much better now.