Spelling is practically interchangeable in the United States. However, an institution can use the most original form of spelling to be associated with the meaning and classical principles of the discipline. The American Association for Orthopedic Surgery uses classic spelling. There is no difference in these two terms with respect to what they mean.
However, some organizations prefer one spelling over the other. In general, “orthopedics” is considered the most pedantic or academic use of the term, while orthopedics is the most Americanized use of the word. There is no semantic difference between the words “orthopedic” and “orthopedic”. Both mean the same thing.
The difference is only in the spelling. Older organizations, such as the American Orthopedic Association (AOA), were founded in 1887, long before the word's spelling was changed. The orthopedist's spelling with e is quite common today, but it is incorrect because it relates the term to the foot, since in Latin pedis is the foot. No matter how it is spelled, an orthopedist provides significant help to patients struggling with problems in their musculoskeletal systems.
However, the US version seems to be gaining ground in recent years, but orthopedics is still the preferred spelling in American spelling.