What Is It?

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 midsection (shaft) of one of the three arm bones (the humerus, radius and ulna).

Fractures of the humerus (upper arm bone)
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 and is sometimes called a “spiral fracture” or a “ball-thrower’s fracture.” These fairly rare injuries tend to affect arm wrestlers and throwing athletes, especially pitchers, javelin throwers and discus throwers.

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 (average age 62), while 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. 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.

In the United States, forearm fractures are the reason for more than 750,000 office visits to orthopedic surgeons every year. Among young Americans, forearm fractures are common in teen-agers who fall while roller skating, in-line skating or skateboarding, while osteoporosis is a common risk factor for older persons with a forearm 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 or shortening of the arm compared to your uninjured arm (if pieces of fractured bone are separated far apart)
• Portions of fractured bone are 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:

• Mild symptoms may include pain, swelling, tenderness, and limited motion near the area of broken bone.
• More severe fractures may result in bruising and may cause deformity of the forearm, loss of normal arm motion, and numbness in the wrist or hand.
• In an open fracture, parts of the fractured bone (or bones) will be visible through broken skin.

After reviewing your symptoms, the doctor will want to know:

• How and when your injury happened
• Your medical and orthopedic 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, and will check for swelling, deformity, abrasions, bruising and limited motion. He or she also will press gently and feel along the length of your arm to identify any areas of tenderness. To help determine whether a sharp edge of broken bone has damaged any of your arm’s blood vessels or nerves, your doctor will feel your pulse and check your sensation and ability to move your arm and hand. To confirm the location and severity of your fracture, the doctor will order X-rays of the injured bone and sometimes additional X-rays of the joints directly above and below the 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 in as a few as six to eight weeks in young, healthy patients. However, more serious humerus fractures may take more than 12 weeks to mend, especially in elderly people.

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

Protective gear, such as wrist and elbow guards worn by skateboarders, can help prevent arm fractures.

Fractures of the humerus
If the two pieces of broken bone have not separated from one another, your arm can heal after it is immobilized in a special splint or cast.

For a more severe fracture, or any open fracture with exposed bone, the humerus will be repaired surgically with metal pins, or with plates and screws. If you have an open fracture you will be given antibiotics intravenously (into a vein) to prevent infection in the exposed bone.

Once your fractured humerus starts to heal, you will need physical therapy to restore normal strength in your arm muscles and normal range of motion in your elbow and shoulder. Healing and physical therapy 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. If a fracture involves only minor separation, an orthopedic doctor may be able to realign the fragments of your broken bone while you are under anesthesia, in a treatment called closed reduction. Then, your arm will be immobilized in a long arm cast, which extends from your knuckles to your upper arm, above your elbow.

A more severe fracture, or an open fracture with exposed bone, will be repaired surgically using metal plates and screws or surgical wires. If you have an open fracture you will be given antibiotics intravenously (into a vein) to prevent infection in the exposed bone. 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.

If your arm hurts severely or pain lasts after an injury, you should call a health-care professional to 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, even if the injury itself seemed minor.

For most fractures of the humerus, the prognosis is excellent, especially in people age 35 and younger. After proper treatment and rehabilitation, more than 90 percent of patients regain full strength and range of motion in the injured arm.

The prognosis is also excellent for most forearm fractures. In 91 percent to 97 percent of patients, the broken bones heal successfully.

Diseases and Conditions Center

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.