All jargon is essentially a shorthand way of labeling stuff. While "femur" may be in common enough use as not to be considered jargon his particular use of "subframe" in this context is, IMHO, uncommon enough to be considered jargon as far as the general public are concerned.
A more appropriate comparison would be the term "medial epicondyle" which is medical "jargon" for "funny bone". I doubt if that many members of the public would be aware of what you were referring to if you called it by its "correct" term.
Basically, once you know the meaning of a term (in any trade) it ceases to be jargon. I was acting as a TA to some first year students during a problem solving session when several complained about the convoluted wording of the simulated report they were being asked to comment on and "solve". I can't remember the exact wording but it went something like this:
" 3mth primigravida, complaining of bitemporal hemianopia, periorbital pain, gynaecomastia and lactation. What further investigations would you suggest be carried out. "
Now, any medical practitioner worth his salt would recognize it as a classic problem posed by examiners and a favourite of professors when testing students. But because these were "newbie"students and had only been in med school for a few months they were overwhelmed by the terms above. Although it was explained to them that they would have come to terms with this type of language as they would be meeting it (and worse) throughout their career many were still rather resentful and even angry, feeling it to be unnecessary. Though when they were asked what alternative words they'd have used they were stumped and realised that there was rhyme and reason for that terminology being employed in that manner.
Heh, yes, yes, everything is "obvious" once you know what it means and how and where all the "pieces" fall into place :)
Please note that when I used the term "jargon" it was with air of someone bemused by the whole thing rather than someone seeking to criticise his use of words. I, of all people, know that sometimes there's no easy of avoiding the use of jargon.