The radius and the ulna are bones in the forearm. Fractures, or breaks, of the radius and ulna are among the most common bone injuries.

People may sometimes fall on their arms or use them to brace against a fall, which can result in fractures of the radius and ulna.

Fractures can be very painful, but the outlook is very good with treatment. Most people can recover fully.

Treatment may include surgical and nonsurgical interventions. Surgery may be necessary for some adults, for example, if the bone juts out of the skin or damages blood vessels.

Read on to learn more about fractures of the radius and ulna.

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The radius and ulna are the two long bones in the forearm. The radius is the bone on the thumb side, closer to the body, while the ulna is on the same side as the pinkie. These two bones rely on each other for support.

Fractures can cause varying degrees of pain. A fracture may be immediately and intensely painful or may cause only mild pain or aching. A person cannot tell whether they have a fracture based on how intense the pain is, especially if the fracture does not visibly change the shape of the arm.

Fractures sometimes affect the growth plate in children and teens who are still growing. This is where new bone grows, so specialized treatment is important to ensure typical growth.

The type of radius or ulna fracture a person sustains will directly affect:

  • how severe the injury is
  • how long recovery takes
  • the treatment plan a doctor might recommend

Common types of forearm fractures include:

  • Metaphyseal fracture: This affects either the upper or lower portion of the bone but does not affect the growth plate in children.
  • Torus or buckle fracture: This causes the top layer of bone to compress, forcing the other side of the bone away from the growth plate. The broken pieces remain in position and do not separate.
  • Greenstick fracture: This goes through a piece of bone, causing the bone to bend on the other side of the fracture.
  • Monteggia fracture: This affects both the radius and the ulna. It can dislocate the top portion of the radius. This is a more serious fracture that requires emergency care.
  • Galeazzi fracture: This affects both the radius and the ulna, usually at the wrist, where the two bones meet.
  • Growth plate fracture: This injury, which affects children and teens who are still growing, occurs in the growth plate, usually in the radius near the wrist. It requires urgent specialist care.

Doctors may use imaging tests, such as X-rays or MRIs, to confirm the diagnosis.

Learn more about how doctors diagnose fractures here.

Falling onto the hand or arm is the most common cause of forearm fractures. For example, a person might put their arms out to brace themselves when they fall down stairs or while roller skating. Other possible causes include:

  • car accidents
  • sports injuries
  • falls from heights, such as a wall or a play structure

Sometimes a disease such as osteoporosis weakens the bones, increasing the risk of fractures from minor falls.

Nonsurgical treatment may work well for simple fractures in which the bone does not move out of place or come through the skin.

A doctor may recommend a cast, splint, or brace. This will depend on many factors, including the location and severity of the fracture and the specific treatment plan.

In most cases, the bone will heal on its own without ongoing pain or stiffness. Sometimes, over-the-counter medications, such as acetaminophen (Tylenol), can help with pain management.

However, some people may need physical therapy to regain full function.

Doctors may reserve surgery for certain cases.

Is surgery always necessary?

Surgery is not always necessary. If the bone is broken but not out of place, a cast or splint may allow it to repair itself.

A person may need surgery if:

  • both bones are broken
  • one of the bones is broken and out of place
  • bone comes through the skin

What might surgery involve?

A surgeon will make an incision in the skin to expose the fracture site and then move the broken bone back into place while the person is fully asleep under anesthesia. They will then secure the bone in place with pins or metal implants. However, this is not always necessary, and a person may need only a cast.

Doctors use a variety of surgical approaches. Many open surgeries carry a risk of infection, and bone infections are typically difficult to treat.

A person who wants to better understand the process should ask a healthcare professional about the surgery and recovery.

Healing time varies from person to person. It can depend on many factors, including:

  • the treatment a person undergoes
  • the type of fracture they have
  • their overall health status

Less serious fractures that require only a cast or splint often heal in 3–4 weeks.

More severe fractures may take longer to heal, around 6–10 weeks.

After a doctor removes a cast, a person may feel stiffness for several weeks. If this stiffness persists, a person might need physical therapy.

After a fracture, a person should not do any exercises without first consulting a doctor. In the early days after an injury, it is often important to immobilize the injured area. However, as it heals, certain exercises may help.

Wrist exercises, such as rotating the wrist clockwise, counterclockwise, or forward and backward, may help improve range of motion.

After a cast comes off, it is important to avoid activities that could re-injure the break, such as contact sports and climbing, for 3–4 weeks.

With treatment, complications are not typical. However, they are more likely to occur with more severe fractures. Potential complications include:

  • wound site infection if the fractured bone protrudes through the skin
  • postoperative infection from wound contamination during or after surgery
  • compartment syndrome, which causes intense pain when an internal hemorrhage restricts blood flow to the muscles
  • incomplete healing, which may happen if the bone does not fully fuse back together or if a person delays treatment
  • stiffness, pain, or numbness after the removal of a cast
  • bleeding after surgery or if a fractured bone severs blood vessels

With treatment, the outlook is excellent. Two months after the injury, the bone has usually fused back together. Most people regain full function.

However, complications can slow recovery or affect the outlook, so it is important to seek prompt medical care for a bone fracture and follow a doctor’s instructions to speed up recovery.

In people with osteoporosis, it is important to treat the underlying disease and not just the fracture. Treatment for osteoporosis may decrease the risk of subsequent fractures.

A fracture of the radius or ulna can be very painful. If the bone comes through the skin or juts very far out of place, it is an emergency and can cause infection and other complications.

The two bones rely on each other for support, so treatment should focus on aligning them to prevent future problems.

A person should seek medical care after a fall or any other serious injury if they have significant pain. They should seek emergency care if the arm looks misshapen or the bone is visible.