Advanced fracture. Is there any hope?

My dear 9-month-old kitty was attacked by a dog, causing an advanced femoral fracture. The fracture is somewhat diagonal as shown on the x-ray. She has undergone two attempts at stabilizing the fracture using a plate and screws, but after 2-3 weeks, the stabilization started to fail both times. Neither I nor the vet understand why this is happening. He says the screws were tight and that a young cat should be healing well. She only eats high-quality kitty food, and after the second surgery, she has mostly been kept in a large dog cage to stop her from jumping and running. My theory is that either the bone is rejecting the screws and pushing them out, or the diagonal fracture provides too little bone on each side for the screws to really sit tight. When she was first bit, she also had a massive, dark bruise covering most of her thigh, which has since gone away. I have added an x-ray of the fracture and the first surgery attempt.After a while, the plate started to become loose from the lowermost piece, eventually collapsing completely. Can anything be done at this point?

First surgery, which eventually failed.

Hello - thank you for sharing this interesting case.  As ever, no-one wants their pet to be an 'interesting case' - we'd all rather that any necessary surgeries were uncomplicated and routine.  I'd also - cards on table here - rather that my patients were medical cases.  I have always referred more complex surgical cases to an expert in the field.  For example, someone who does orthopaedic cases all day long and is therefore more experienced in them than your average GP vet whose attention is split between orthopaedics, peadiatrics, exotics, endocrine, infectious diseases, obstetrics, routine public health, oncology and so on.  You don't mention the experience of the vet who looked after your kitten (and not every case goes well even for top orthoaedic surgeons in specialist hospitals) but it sounds as though they've had a couple of goes at repairing the leg, so it might be a good time to ask whether there is someone more specialised available to offer advice.  That wouldn't be me - as I said, it isn't my area.  However, I did wonder a couple of other things;  1) since this was a bite wound, could the sterility of the area or implant have been compromised?  Has the infection resolved?  Could this cause the failure to struggle to heal? And 2) the screw that may be penetrating the opposite cortex - was that a) intentional or b) problematic if it wasn't?   Also, I find a good question to be, Is an amputation or repeat fracture repair most advisable now, at that this stage?  This should always be considered in the light of the budget available.  Good luck in taking the case forward and I would be interested to hear how you get on.