Which category of anomalies includes extra bones such as additional carpals or metacarpals?

• A. Accessory foramina
• B. Non-fusion anomalies
• C. Accessory bones
• D. Deformative

Answer: (C)

Extra bones in the hand, such as additional carpals or metacarpals, are described as accessory bones. These arise when additional ossification centers persist during development, producing a bone that sits alongside the normal skeletal elements rather than replacing them. This category is distinct from accessory foramina, which are extra openings; non-fusion anomalies, which involve incomplete joining of bones during growth; and deformative changes, which are alterations in shape from injury or disease. In short, extra, nonstandard skeletal elements are best classified as accessory bones.