Of Interest: "Nicholas Andry coined the word "orthopaedics", derived from Greek words for "correct" or "straight" ("orthos") and "child" ("paidion"), in 1741, when at the age of 81 he published Orthopaedia: or the Art of Correcting and Preventing Deformities in Children.
In the U.S. the spelling "orthopedics" is standard, although the majority of university and residency programs, and even the AAOS, still use Andry's spelling. Elsewhere, usage is not uniform; in Canada, both spellings are common; orthopaedics usually prevails in the rest of the Commonwealth, especially in Britain."  (Source: Wikipedia.org)