Not very!!
http://www.google.com/search?rlz=1C2GGGE_enUS379US455&hl=en&source=hp&biw=1366&bih=643&q=how+effective+were+medieval+doctors&gbv=2&oq=how+effective+were+medieval+doctors&aq=f&aqi=&aql=&gs_sm=e&gs_upl=2625l8384l0l11004l3l3l0l0l0l0l254l672l2-3l3l0
Read widely.
how affective were mediaeval doctors?
2 answers
if u had to have a leg removed or an arm basically you would still be awake, pinned down, have no painkiller and you would feel everything