Following the index, I'm seeing M00.9
Arthritis, septic (any site except spine) directs to see also Arthritis, pyogenic or pyemic
Arthritis, pyogenic or pyemic (any site except spine) has a default code of M00.9. There are some subcategories for bacterial, streptococcal, etc, but those don't match up with the information provided.
So...I'd stick with the default listed code of M00.9 (Pyogenic arthritis, unspecified/Infective arthritis NOS).