The forearm consists of two bones, the radius and the ulna, with the ulna is located on the pinky side and the radius on your thumb side.

Fractures of the forearm can occur at different levels: near the wrist at the farthest (distal) end of the bone, in the middle of the forearm or near the elbow at the top (proximal) end of the bone. They can occur through a direct blow (a fall on the forearm or direct impact from an o bject) or indirect injury. The latter is usually secondary to landing on an outstretched arm.

The primary motion of the forearm is rotation: the ability to turn our palms up or down. The ulna stays still while the radius rotates around it. This is the motion used to turn a screwdriver or twist in a light bulb. Forearm fractures can affect your ability to rotate your arm, as well as bend and straighten the wrist and elbow.

Cause

The most common causes of forearm fractures include:

  • Direct blow
  • Fall on an outstretched arm, often during sports or from a height
  • Automobile/motorcycle accidents

Symptoms

A broken forearm usually causes immediate pain. Because both bones are usually involved, forearm fractures often cause an obvious deformity — your forearm may appear bent and shorter than your other arm. You will most likely need to support your injured arm with your other hand.

Additional symptoms include:

  • Swelling
  • Bruising (not as common as in other broken bones)
  • Inability to rotate arm
  • Numbness or weakness in the fingers or wrist (rare)

Forearm fractures can cause further injury and complications.

  • The ends of broken bones are often sharp and can cut or tear surrounding blood vessels or nerves.
  • Excessive bleeding and swelling right after the injury may lead to acute compartment syndrome, a condition in which the swelling cuts off blood supply to the hand and forearm. It typically occurs within 24 to 48 hours of the injury and causes severe pain when moving the fingers. Compartment syndrome can result in loss of sensation and function, and requires emergency surgery once it is diagnosed. In such cases, the skin and muscle coverings are opened and left open to relieve pressure and allow blood to return.
  • Open fractures expose the bone to the outside environment. Even with good surgical cleaning of the bone and muscle, the bone can become infected. Bone infection is difficult to treat and often requires multiple surgeries and long-term antibiotics.

There are risks associated with all surgery. If your doctor recommends surgery, he or she thinks that the possible benefits of surgery outweigh the risks.

  • Infection. There is a risk of infection with any surgery, whether it is for a forearm fracture or another purpose.
  • Damage to nerves and blood vessels. There is a minor risk of injury to nerves and blood vessels around the forearm. Although some temporary numbness is common right after your injury, if you experience persistent numbness or tingling in your fingers, contact your doctor.
  • Synostosis. Another rare complication is healing between the two bones of the forearm with a bridge of bone known as synostosis. This can decrease the rotation of the bones and prevent full movement.
  • Nonunion. Surgery does not guarantee healing of the fracture. A fracture may pull apart, or the screws, plates, or rods may shift or break. This can occur for a variety of reasons, including:
    • The patient does not follow directions after surgery.
    • The patient has other health issues that slow healing. Some diseases, like diabetes, slow healing. Smoking or using other tobacco products also slow healing.
    • If the fracture was associated with a cut in the skin (an open fracture), healing is often slower.
    • Infections can also slow or prevent healing.

Nonsurgical treatmentRehabilitation typically begins after a few weeks of keeping the arm still by using a cast or brace. In many cases, a physical therapist will help with rehabilitation, beginning with gentle exercises to increase range of motion, and gradually adding exercises to strengthen the arm.

Surgical treatmentDepending on the complexity of the fracture and the stability of the repair, a cast or brace may be necessary for 2 to 6 weeks after surgery. Motion exercises for the forearm, elbow, and wrist usually begin shortly after surgery. This early motion is important to prevent stiffness. Your doctor may also prescribe visits to a physical or occupational therapist, depending on how long your arm was immobilized.