I have a question regarding joint replacement, that one of my students, a nurse, asked me.

The question reads: "Patient has been diagnosed with severe osteoarthritis in the joints of his fingers. The physician performs a joint replacement of the index finger". The answer given was 26530. She contends it should be 26535, as a joint replacement of the finger might not include the metacarpal joint. Does anyone have any information I could use on this? Thank you.