Hi and welcome.

I'm sorry the SRS didn't work for your pup- what's his name? 

It probably depends on where the tumor is located.  Are you asking about a hemipelvectomy where they take out part of the pelvis or a full femur vs mid-femoral amputation? Here are the results of a forum search on hemipelvectomy.

I've had two rear amp Tripawds.  My first, TriPug Maggie lost her rear leg to a mast cell tumor.  She had a mid-femoral amputation where a little piece of the femur was left and wrapped in muscle.  Her tumor was in her knee.

My current Tripawd Elly lost her rear leg after being hit by a car.  Her entire femur was removed but all of her pelvis remains.  I don't know if a mid-femoral amputation was possible for her, I adopted her about 2.5 months after her surgery.

If I could choose between full femur removal surgery and a mid-femoral amputation I would choose mid-femoral based on my two experiences.  Maggie, who had part of her femur, had a much more stable sitting platform, she was more balanced standing and her gait was smoother.  I think the weight of the partial femur and the muscle padding allowed her to stand and move more naturally.  Elly, who has no femur left, is uncomfortable sitting on hard surfaces, isn't as balanced standing and her gait is not as smooth. In Maggie's case you could not see her 'stump' but you could see it move under the muscle and I could feel it.  She lived almost 4 years after her amp and never had an issue with her stump.

I'm only talking partial amputation for rear legs, front limb amputation has different considerations and leaving part of the limb is not usually done unless a prosthetic is being considered.

Karen and the Spirit Pug Girls