i've had both mine done
small cut in your wrist about 2 inches long
the op's called carpel tunnel decompression
my hands used to go numb if held any higher than my shoulder for any more than a minute or so
i got pins and needles in my hands all the time
used to wake up several times during the night with hand aching, always had to sleep with arm hanging out the bed to help circulation
got my right done couple years ago and my left done in may this year
dont think it affects shoulders just hands and wrists
and it is directly linked to artritus, its very common in my family, me my mum and my sister all suffer from it