so sorry
sounds like possible acl tear to me as that will not show up on xray but if it was to do with surgery and LP groove not being deep enough and slipping off then i would think that would show up on xray and orthopedic could see that.
when dd had acl injury she lifted leg and did not drag it so that has me a little concerned it is LP Surgey related and not acl as acl at least dd did lifted leg to get it back in line the two bones then would walk on it as the bones slip out of place as no acl to keep in lined up
I guess they could drag but dd never did that so only thing i have to compare it to
MRI is very expensive and our friend who is the head radiologist at a surgical center in los angeles and she use to teach radiology at ohio state vet school and when i called her about dd she said mri is a waste of money as it is hard to see in a big dog that tendon much less a small dog.
here is our friend
Animal Surgical & Emergency Center :: (310) 473-1561
The drawer test and tibial thrust is used to determine acl rupture in dogs. It is best to do those tests upfront before the scar tissue starts so if this just happened take to orthopedic with xrays and discuss and have that test done. It is real easy they take the two bones and if they slide across one another then acl is ruptured if they do not then possible tear. You do not want to wait on that as then if they do it they have to break scar tissue and you have to start from scratch
DD had two months of rest and confinement and was fine as happens in 80% of two breeds. AFter the two months and if still lifting you have to go with surgery