I just want to start with saying, I understand Legg-Calve-Perthes disease better in people. I am sure there are some vets that visit this site, and who might have some advice, but I know how uneasy it can be not knowing stuff immediately. From what I understand, not enough blood flow is getting to the top of Logan's femur - so it's not growing as well as the rest of him, and if the blood supply gets cut off too much for too long, it becomes necrotic - a fancy way of saying the top part of his thigh bone dies. What could potentially happen then is that the head of the femur could collapse (picture an ice cream cone with a scoop on top - think of that scoop kinda falling in) - causing pain, and decreased movement. Sometimes the treatment can be pretty conservative, but if your vet is considering surgery, it is probably a little more advanced, or aggressive.
I don't know about the better treatment options for this situation specifically, but my brother has a Rhodesian Ridgeback (somewhere around 90 lbs) that had to have the head of his femur removed after he was hit by a car when he was younger. And we were very lucky, in that he is still very active, even with some muscle loss (atrophy). Dogs muscles are different from ppl's in that they twist around the bone, so even with removal there is enough structual support so the dog can still move. Recovery, from what I remember, took a while - but our Samson is very happy and active now. And I believe the surgery is easier on smaller dogs...
I'm not sure if any of this helped, or just added to what you already knew...but after having gone through something like this with my brother's Samson, I thought it might be reassuring to hear from people. It sounds like you are taking control of this problem, but if you are discussing something with your vet and he/she says something you don't fully understand - Please, stop him and ask him to explain!!! And ask questions if you have them... When you leave the office, you should have a clear understanding of what's going on because this stuff is overwhelming, esp if you are worried about your little guy...
I don't know if this was of any use...but it sure did turn out longer than expected - sorry!
Logan sure is a cute one, and he's lucky to have you
