My dogs leg is clicking?

I have a 8 year old erspaniel and a few months back he started limping so i got him check and they told me he tore a ligament kinda like an ACL and they told me it would not heal and surgery was the only way to fix it but i kinda dont have $3000+ to get it done, so they told me he might be ok but he would need to lose weight. So he has lost a little weight now and still limps not as bad as it was before though able to walk on it, and just recently his leg started to click, sounds horrible does he need to get the surgery that i cant afford?