Surgery is not recommended for baker's cysts they very often go away by themselves or have anti inflammatory meds ..b171 is an older child so I guess his pediatrician has decided to go with surgery...good luck 171 and thanks for the input let us know how it goes ...
I'm 12 and have a Baker's cyst. not 2 worry you or anything, but i have to have it surgically removed. i can't put any weight on i though so i might have it worse than your child.
Get a second opinion. There's no harm in looking somewhere else other than the doc you have now. There's always risks with surgery, but he's old enough to where the risks should be low.