M13.1 - Monoarthritis, not elsewhere classified
M13.17 - Monoarthritis, not elsewhere classified, ankle and foot
M13.171 - Monoarthritis, not elsewhere classified, right ankle and foot
M13.172 - Monoarthritis, not elsewhere classified, left ankle and foot
M13.179 - Monoarthritis, not elsewhere classified, unspecified ankle and foot