Forearm Anatomy

Forearm fractures are common in childhood, accounting for more than 40% of all childhood fractures. About three out of four forearm fractures in children occur at the wrist end of the radius.

Forearm fractures often occur when children are doing activities like playing or participating in sports. If a child takes a tumble and falls onto an outstretched arm, there is a chance it may result in a forearm fracture. A child's bones heal more quickly than an adult's, so it is important to treat a fracture promptly—before healing begins—to avoid future problems.

The forearm is made up of two bones: the radius and the ulna. The radius is on the "thumb side" of the forearm, and the ulna is on the "pinky finger side." Growth plates are areas of cartilage near the ends of the long bones in children and adolescents. The long bones of the body do not grow from the center outward. Instead, growth occurs at each end of the bone around the growth plate. When a child is fully grown, the growth plates harden into solid bone. Both the radius and the ulna have growth plates.

Fractures can occur in one or both bones of the forearm, and in a number of places along the bone:

  • Near the wrist, at the farthest (distal) end of the bone In the middle of the forearm
  • Near the elbow, at the top (proximal) end of the bone

What are the different types of forearm fractures in children?

There are several types of forearm fractures in children:

  • Torus fracture. This is also called a "buckle" fracture. The topmost layer of bone on one side of the bone is compressed, causing the other side to bend away from the growth plate. This is a stable fracture, meaning that the broken pieces of bone are still in position and have not separated apart (displaced).
  • Metaphyseal fracture. The fracture is across the upper or lower portion of the shaft of the bone and does not affect the growth plate.
  • Greenstick fracture. The fracture extends through a portion of the bone, causing it to bend on the other side.
  • Galeazzi fracture. This injury affects both bones of the forearm. There is usually a displaced fracture in the radius and a dislocation of the ulna at the wrist, where the radius and ulna come together.
  • Monteggia fracture. This injury affects both bones of the forearm. There is usually a fracture in the ulna and the top (head) of the radius is dislocated. This is a very severe injury and requires urgent care.
  • Growth plate fracture. Also called a "physeal" fracture, this fracture occurs at or across the growth plate. In most cases, this type of fracture occurs in the growth plate of the radius near the wrist. Because the growth plate helps determine the future length and shape of the mature bone, this type of fracture requires prompt attention.

What causes a child to break their forearm?

Children love to run, hop, skip, jump and tumble, all of which are activities that could potentially result in a fracture to the forearm should an unexpected fall occur. In most cases, forearm fractures in children are caused by:

  • A fall onto an outstretched arm
  • A fall directly on the forearm
  • A direct blow to the forearm

What are the symptoms that a child has broken their forearm?

A forearm fracture usually results in severe pain. Your child's forearm and hand may also feel numb, a sign of potential nerve injury.