Red my dear -- this seems to be a pretty young calf, I'd say a week or two at most correct??
Although there doesn't seem to be a fever in the joints as you mention, the joint will not always be hot if there is a low grade navel infection. I have had them get it right out in dry ground, so it really doesn't have to be due to a wet environment.
I certainly do not want to sound like a know it all, we all get a calf every so often that is just plain bad for some reason, but one this I always do is give it the benefit of the doubt!! The doubt inthis case would be to assume she DOES have a low grade infection (Good in reality) and go with a one time dose of 10 ml long acting penicillin. The swollen knees are the first sign I look for, and over the years, I can tell you that several calves would have never made it if it weren't for the good old drug. The ones like this may very well be goners, just too straight in the shoulders and hind leg gs, but still -- it is worth a couple dollars to find out.
I give every one a chance to prove to me it is bad structure before I give up. I would get this calf a shot of penn. as fast as possible -- then give it a week -- if it doesn't improve -- it is indeed a cripple instead of an infection. You just never know for sure -- those bucked knees are a sure sign of stress in some way for sure!
Best of luck hon -- bye bye cow!!! hehehehe
Terry