Which bones are described as sesamoid bones in the human body?

• A. Radius and Ulna
• B. Scapula and Clavicle
• C. Tibia and Fibula
• D. Patella and Hyoid

Answer: (D)

Sesamoid bones form inside tendons, usually where a tendon passes over a joint, to protect the tendon and improve leverage. The kneecap is the classic example, sitting within the tendon of the quadriceps as it crosses the knee.

The hyoid bone, on the other hand, is a unique U-shaped bone in the neck that is suspended by ligaments and muscles rather than embedded in a tendon. It doesn’t develop as a tendon-bone within a joint, so it isn’t classified as a sesamoid bone.

So a statement that pairs two bones as sesamoids would only be accurate if both are embedded in tendons; the patella is indeed sesamoid, while the hyoid is not.