on the ACGME website, you can go to the residency review committee link. For orthopaedic there are a couple of RRC's, but you want the residency one. I've included the link to the pdf file at the bottom. Here is the section on PGY-1 requirements.
In order to meet these goals the PGY-1 year must include
a. a minimum of six months of structured education in surgery, to
include multi-system trauma, plastic surgery/burn care, intensive
care, and vascular surgery;
2
b. a minimum of one month of structured education in at least three
of the following: emergency medicine, medical/cardiac intensive
care, internal medicine, neurology, neurological surgery, pediatric
surgery or pediatrics, rheumatology, anesthesiology,
musculoskeletal imaging, and rehabilitation; and
c. a maximum of three months of orthopaedic surgery.
Hope this helps, and good luck.