why did i not have to have my arm raised the second fusion?

i have had both joints in my right thumb fused (i had 2 operations when i was a baby on my thumbs but i cant remember them because i was 1 and 2 at the time) and when i got the first fusion in the children s hospital i had to have my arm in a sling hanging of a drip pole. the second fusion in the adult hospital i did not have to have this, not even a sling. i also had to have the wires taken out, both in the adult hospital, as we now know i have an extreme allergy to metal, and no sling then either. the last 3 operations i woke up with my arm lying down beside me but the first fusion i woke up with my arm already in the sling and it was propped up beside me so my hand was in the air and as soon as i got back to my room they hung my arm off a drip pole. the hospital i go to is absolutely offal and my mum thinks that's the reason.