Did you try getting a second opinion/other vets price range?

From little medical knowledge I have, and from watching lots of Emergency
vets, I think that sedation is still a mild anestethic, which might take a
few hours to recover from correctly. Animal needs to be under medical
observation while coming around. The vets have to make sure liver clears out
all the sedative/anestethic leftovers. If animal is not in her/his prime,
and yours one is , bless, now in the older age group, the supervision has to
be tighter.

The x-ray has to be taken while the animal is completely still, so even
though she sleeps for you, she may panick at the vets, and not want to sleep
on that particular table in the particular needed position. Hence the
sedative.

There is a chance she may have artritis, which lots of cats get at around
this age. Start her on some human Cod liver oil and see if it helps. Give
her oil from the capsule mixed in food say 3 times a week. It won;t harm her
anyway , even if it;'s not arthritis. She could;ve also sprayned the leg.
She is an old lady now, and old ladies become more frail. Hopefull it;s
nothing worse then that, but for an older cat it could take months to
recover properly. With both of the above she will still use the leg to walk,
and heroically handle the pain. Animals rarely cry if they are in serious
discomfort.

Fanlly try posting medical question to alt.med.veterinary group and see what
they suggest.

Gee