capitellum

The capitellum is a rounded, knoblike structure at the end of the humerus (the upper arm bone) that forms part of the elbow joint. It helps connect the upper arm to the bones in the forearm, allowing for smooth movement such as bending and turning the arm. The capitellum interacts with the radius (one of the forearm bones), providing stability and enabling rotating motions. It is essential for proper elbow function, especially during activities involving weight-bearing or lifting. Injury or damage to the capitellum, such as fractures or cartilage issues, can impair elbow mobility and cause pain.