Orthopedic concerns about failed bone graft

Dear Ask The Doctor: I've had ACL reconstitution, which failed. not happy with results. I went to another hospital. They gave me an MRI scan, the orthopedic doctor was shocked to find that i had no screws or owt in place to hold the graft, I'm worried by her reaction, she said that she was going to consult the surgeon's notes. So now they are planning 2 operations, 1)to take bone from my hip to fill the holes in, 2)attempt another graft..my question is, the first graft I had, how come it has left holes? Should it not be plugged to hold the graft?

Dear Ricky: The 'holes' noted on the MRI exist because the bone graft failed, These holes are the vacant spaces in which new bone was expected to grow. However, this did not occur hence the holes still exist. Your surgeon will attempt to fill these holes with bone from your hip during the second operation.