Arm Fracture

What is an arm fracture?

When a bone breaks or cracks, the injury is called a fracture.

In the arm, a fracture most often occurs in the long and slender shaft of one of the three arm bones. The three arm bones are the humerus, radius, and ulna.

Fractures of the humerus (upper arm bone)

The humerus is the bone that extends from the shoulder to the elbow.

In otherwise healthy people, most fractures of the humerus are caused by a direct blow to the upper arm. This often is caused by a motor vehicle accident or high-impact fall. Less often, the humerus can fracture because of a severe twist of the upper arm, a fall on an outstretched arm, or an extreme contraction of upper arm muscles.

If the bone fractures because of an extreme muscle contraction, the break curves around the bone. This is sometimes called a spiral fracture or a "ball-thrower's fracture." These injuries are fairly rare.

If the humerus breaks because of a low-impact bump or fall, this may mean that the bone has been weakened by an illness such as osteoporosis or cancer. These are called pathologic fractures. Cancer-related fractures of the upper arm bone tend to occur in older people. Trauma-related fractures of the humerus tend to affect younger people.

Fractures of the radius and ulna (forearm fractures)

The forearm contains two bones, the radius and the ulna. Both extend from the elbow to the wrist. The radius is on the same side of the arm as the thumb. The ulna is on the side of the little finger.

When the forearm is fractured, either the radius or ulna may be fractured alone, or both bones may be fractured. In either case, the injury is almost always caused by a direct blow to the forearm, or by falling on an outstretched arm.

Among young Americans, forearm fractures are common in teenagers as a sports-related injury or skateboarding. Osteoporosis is a common risk factor for older persons with a forearm fracture.

Symptoms of an arm fracture

If you have fractured the shaft of your humerus, your symptoms may include:

pain, swelling, tenderness, and bruising in your upper arm
limited motion in your upper arm and shoulder
deformity of your injured arm
shortening of the arm compared to your uninjured arm (if pieces of fractured bone are separated far apart)
parts of fractured bone visible through broken skin (an open fracture).

If you have fractured one or both of the bones of your forearm, your symptoms will vary depending on the severity of your fracture. Symptoms may include:

pain, swelling, tenderness, and limited motion near the area of broken bone
- bruising
- deformity of the forearm
- loss of normal arm motion
- numbness in the wrist or hand
- parts of the fractured bone (or bones) may be visible through broken skin (an open fracture).

Diagnosing an arm fracture

The doctor will review your symptoms. He or she will want to know:

how and when your injury happened
your medical history, especially any history of previous injuries to your arm including your shoulder, elbow, and wrist
the approximate date of your last tetanus immunization (if your injury broke the skin).

Your doctor will compare your injured arm with your uninjured one. He or she will check for:

swelling
deformity
abrasions
bruising
limited motion.

Your doctor will press gently and feel along the length of your arm to identify any areas of tenderness.

Your doctor will feel your pulse and check your sensation and ability to move your arm and hand. This will help determine whether a sharp edge of broken bone has damaged any of your arm's blood vessels or nerves.

The doctor will order x-rays of the injured bone. Sometimes additional x-rays of the joints directly above and below the fracture will be ordered as well. The x-rays will confirm the location and severity of your fracture.

Expected duration of an arm fracture

Small fractures of the forearm heal in about four weeks when immobilized in a cast. More severe forearm fractures may need to be repaired surgically, and then immobilized for up to 12 weeks.

Small fractures of the humerus may heal within eight weeks in young, healthy patients. However, more serious humerus fractures may take more than 12 weeks to mend. This is especially true in elderly people.

Up to six months of rehabilitation exercises can be necessary for muscle and strength to recover after forearm and humerus fractures.

Preventing arm fractures

If you have or are at risk of developing osteoporosis, talk to your doctor. Ask about strategies to improve bone strength and prevent age-related bone loss. Strategies may include:

weight-bearing exercise
calcium and vitamin D supplements
preventive or therapeutic medications.

Protective gear can help to prevent arm fractures. Examples include wrist and elbow guards worn by skateboarders.

Treating arm fractures

Fractures of the humerus

The vast majority of humerus fractures are treated without surgery. The arm can heal after it is immobilized in a cast, a special splint, or a functional brace.

Surgery may be needed for a more severe fracture, or any open fracture with exposed bone. The humerus will be repaired with plates and screws, or a metal rod. If you have an open fracture you will be given antibiotics intravenously (into a vein). Antibiotics help prevent infection in the exposed bone or nearby tissues.

Once your fractured humerus starts to heal, you may need physical therapy. Physical therapy helps to restore normal strength in your arm muscles. It also restores normal range of motion in your elbow and shoulder. A course of physical therapy for a fractured humerus usually takes several months.

Fractures of the forearm

It is common for the fragile bones in the forearm to be separated from each other during a fracture. Forearm motion is very important. As a result, only the mildest fractures — including those that are nondisplaced — are treated without surgery. A typical treatment for a nondisplaced forearm fracture includes wearing a cast for six weeks.

A more severe forearm fracture, or an open fracture with exposed bone, will be repaired surgically. Metal plates and screws may be used. If you have an open fracture you will be given antibiotics intravenously to prevent infection.

Your doctor may prescribe physical therapy to help restore your arm's strength and mobility. For children with mild fractures, a few simple arm exercises may be enough to return the injured arm to normal. These exercises usually can be done at home. A cast is usually not required after forearm surgery. For people with forearm fractures due to osteoporosis, medications to improve bone health (such as calcium, vitamin D, and alendronate) are generally recommended; this can reduce the risk of future fractures.

When to call a professional

Call your doctor if your arm hurts severely or pain lasts after an injury. He or she can determine if a bone may be fractured.

You also should see a health care professional after an injury that results in numbness or weakness in the hand or wrist. This is true even if the injury itself seemed minor.

Prognosis

For most fractures of the humerus, the outlook is excellent, especially in people ages 35 and younger. After proper treatment and rehabilitation, most patients regain full strength and range of motion in the injured arm.

The prognosis is also excellent for most forearm fractures. In most patients, the broken bones heal successfully.