in my opinion the dog needs on iv antibiotics a couple weeks ago , possibly more than one kind , as someone who has spent a large portion of my lifes earnings on antibiotics for animals , clindamycin is close to worthless , clavamox better , but not much ........ i'm thinking the hard tissue you feel has nothing to do with the body protecting the plate , the body does not protect inert foreign objects , it rejects them , the hardness is tissue inflammation , cellulitis ...... imo , there is a lot of things to be tried before amputation . it does come down to amputation sometimes , not always , it is a last resort ....... given the right antibiotic , the pain and swelling will subside , the atrophy you see is not as bad as it appears ........ surgically opening the wound , draining it , putting antibiotics right in it , they got antibiotic beads they can implant right in the wound , debriding any dead tissue ..... but I guarantee you that dog needs to be on iv antibiotics , something good , maybe more than one type ........... does he have a fever ? I would assume not given the bloodwork came back good ............