Question: Encounter notes indicate that a patient suffered from periprosthetic fracture near an internal prosthetic left ankle joint. I reported M97.22 and the code was rejected. Did I choose the wrong ICD-10 code for this condition? Utah Subscriber Answer: You were on the right path — but your diagnosis code as it stands is incomplete. The entry for M97.22 (Periprosthetic fracture around internal prosthetic left ankle joint) includes a 7th character symbol. That means that for this diagnosis, you need to report an additional 7th character with a placeholder X in the 6th character slot. Do this: Go back and check the notes to see if the encounter for this injury is initial, subsequent, or sequela. Then choose one of the following codes as your final diagnosis: