American Academy of Professional Coders (AAPC) Practice Exam

Which bone classification includes the patella?

1. Flat bones

2. Short bones

3. Sesamoid bones

4. Long bones

The correct answer is: Sesamoid bones

The patella, commonly known as the kneecap, is classified as a sesamoid bone. Sesamoid bones are typically small, round bones that are embedded within tendons. They function to modify pressure, reduce friction, and improve the mechanical advantage of muscles. In the case of the patella, it is located within the quadriceps tendon, which helps it to provide greater leverage for the muscles that extend the knee. By being situated in this tendon, the patella enhances the efficiency of movement and contributes to the stability of the knee joint. Other classifications of bones, such as flat bones, short bones, and long bones, have distinct characteristics and functions. Flat bones generally provide protection and surface area for muscle attachment, short bones are often somewhat cube-like and provide stability while allowing some motion, and long bones, as the name implies, are longer in shape and primarily serve as levers for movement. Understanding the classification of bones is crucial in fields such as anatomy and medical coding, as it helps to determine treatment approaches and codes used in documentation and billing processes.