DS had an appointment to USAFA and had accepted it. Had a knee issue which we informed DoDMERB about. He became medically unqualified, but, didn't lose his appointment -- just had to be medically cleared prior to I-day.
He had surgery in mid March (his was removal of a cyst type growth around a ligament, but ligament in tact), completed PT and was released by orthopedist, with those magical words of something to the affect "no restrictions, complete recovery, etc" - (orthopedist was retired Army so she knew what to write so DoDMERB would understand) on May 1st. We overnighted ALL of his paperwork to DoDMERB (orthopedist appts, surgical report, PT reports, etc). Was requalified medically by DoDMERB by 15 May. He will graduate USAFA this May.
Don't hide anything from DoDMERB but keep all medical records so you can send them copies. If you need surgery, get it sooner rather than later so you can fully recover.
A side note -- we did send in a deposit to his Plan B school in late April because he was not yet medically cleared and we didn't want to lose the full academic scholarship he had to that school. We also didn't withdraw him from Plan B school until completion of BCT, in case his knee had an issue (though he didn't know that). We lost the deposit, but it was well worth the piece of mind we had that he had a place to go should he have a medical issue during BCT.