These are also the nine main sub-specialty areas of orthopedic surgery.

Hand surgery and, more recently, Sports Medicine are the only truly recognized sub-specialties within orthopaedic surgery by the Accredited Council of Graduate Medical Education (ACGME). The other sub-specialities are informal concentrations of practice. To be recognized as a hand surgeon or sports surgeon, a practitioner must have completed an ACGME-accredited fellowship and obtained a Certificate of Added Qualifications (CAQ) which requires an additional standardized examination.