So this is an established patient visit

There is a detailed hx and a detailed exam. The area of disagreement is the MDM. The patient has only the one established problem, that is not worsening. There is no data/tests to review. The plan of care is "lifting capacity will be raised to 30 pounds. He should follow up in 3 months time. In the interim he is to continue strengthening."

So to me, this is straightfoward MDM.
Diagnoses: One established problem, not worsening = straightfoward
Amount & complexity of data is minimal/none = straightfoward
Risk – presenting problem could be low, but diagnostic procedures ordered and management options would only be minimal = straightfoward

The physician feels that this visit is definitely not a 99212. He thinks it should be a 99213, even though I explained that the MDM is the overarching criteria in choosing your code level. He told me, these problems have orthopaedic levels of complexity that are not fully appreciated by one without an orthopedic background.

I admit, I am new to ortho coding, so I am looking for your opinions. What would you code this visit as?