I need help quick please ... My doc has a patient who's knee is not healing appropriately after numerous surgical repairs.

Now the doc wants to implant a morphogenic protein substance into the knee, i believe as a open procedure, to stimulate bone growth in the patient.

He also is going to use the bone stimulator which is not much of a coding question for me.

The big question is ... Does anyone know of a specific code for the grafting procedure for the synthetic substance he wants to graft to the bone?

I'm at a loss except for the unlisted 27899 code ... Any help out there?