Article 450 describes the use of additional ground when wiring for medical offices.

My question is, when using MC Green (which has an additional wire that is aluminum) what do you do with that wire and what is the ground wire for?

Joe,
Um... Article 450? I think it's Article 517. The section that requires that the MC cable shall have an outer sheath assembly that itself qualifies as a grounding conductor is 517.13(A) and (B).
The aluminum Bonding/Grounding conductor is folded back against the outer sheath before insertion into a connector that tightens against the Bonding/Grounding conductor and the outer sheath...
The insulated green ground conductor is terminated to the enclosure and equipment connected to it just like every other ground conductor.

article 450 describes the use of additonal ground when wiring for medical offices.

My question is, when using MC Green (which has an additional wire that is aluminum) what do you do with that wire and what is the ground wire for?
What is your role in this job?
Are you actually coming to a DIY site asking questions on how to wire a medical office?