There isn't a specific category for application of ex-fix as far as I know. It depends on what the actual procedure is that you are doing. If we're just throwing an ex-fix on a fracture to hold it out to length and planning to come back and fix it later, then we don't really log it. If we're using it as part of another procedure, then we log that procedure. As far as PRR is concerned, applying an ex-fix for a procedure is no different than doing internal fixation as far as I have ever heard. I don't claim to be an expert on logging cases by any stretch of the imagination, but that's how I would do it.