Springer spaniel needed screw through elbow!

My 5 year springer broke his leg, the vet advised that he has weak elbows, the bone hasn't completely joined on the elbow therefore causing weakness, he had the break pinned and a screw through his elbow. The screw managed to break so he had to have a stronger screw and a plate on the break, this screw moved so he now has a horse screw which seems to be working but now has an infection! Has anyone else been through this?

If this leg eventually heals I then have to decide wether to have a precautionary screw put in the other elbow.
I would be most grateful for comments.