Orthopaedist: An orthopaedic surgeon, a doctor who corrects congenital or functional abnormalities of the bones with surgery, casting, and bracing. Orthopaedists also treat injuries to the bones. Sometimes spelled orthopedist.
The spelling of "orthopedist" with an "e" is quite common today but it is incorrect because it relates the term to the foot since in Latin "pedis" is the foot. "Orthopaedist" with an "ae" is the correct spelling. What was meant by the term "orthopaedics" when it was devised goes back to its roots: "ortho-", straight + the Greek "paes", child = straightening the child. If a child had a crooked spine (scoliosis), it was the job of the orthopaedist to straighten the child, not just the child's foot.