Fracture of the Humeral Shaft
A fracture of the humeral shaft is a loss of continuity in the humerus, the large bone in the upper arm extending from the elbow to the shoulder. The fracture may be complete, with the broken bone entirely separated, or incomplete or "greenstick type."
A fracture of the humeral shaft involves damage to the humerus, the elbow and shoulder joints, and to soft tissue around the fracture site, including nerves, tendons, ligaments, and blood vessels. The vast majority of these fractures can be treated conservatively (without surgery) with a high degree of success.
Causes of a Fracture of the Humeral Shaft?
A humeral shaft fracture may be the result of direct stress, such as a blow to the arm occurring during an accident in a motor vehicle. Sometimes the humerus will fracture during a fall onto an outstretched arm. Because these fractures are often the result of high-energy trauma, there may be injuries to other parts of the body. Twisting or torsional forces may cause a spiral fracture as with arm wrestling. Children under 12 and adults over 60 are most vulnerable to this kind of injury.
The risk of a fracture of the humeral shaft also increases with:
- Contact sports such as football or hockey
- A history of bone or joint disease, especially osteoporosis
Symptoms of a Fracture of the Humeral Shaft?
If you have fractured your humeral shaft, you will feel severe arm pain and loss of strength in the grip at the time of injury. The soft tissue around the fracture will swell. There will be visible deformity if the fracture is complete and the bone fragments separate enough to distort the normal contour of the arm.
The arm will be tender to the touch. If the blood supply is impaired, there may be numbness and coldness in the arm and hand.
As in the case of any suspected fracture, seek medical care as soon as possible. Many tissues quickly lose their elasticity and must be promptly treated in order to assure maximum healing. Immediately after injury, use blankets to decrease the possibility of shock. Cut away clothing, if possible, but do not move the injured arm to do so.
Follow directions for R.I.C.E.:
- Rest the injured area as much as possible.
- Ice the injury to reduce blood flow and limit swelling.
- Compress the injured joint according to your doctor's instructions.
- Elevate the arm to help control swelling.
Your doctor will examine the arm for neurovascular damage and take x-rays of the injured area, including the joints above and below the primary injury site. He or she will ask for details about how the injury occurred, and will need to know about previous conditions of the arm, hand, and shoulder.
Sometimes the radial nerve is injured during a humeral fracture. This nerve, which supplies sensation to the arm and forearm, may become entrapped at the fracture site. Your doctor will check for this complication, testing for feeling across the back of the hand and asking you to flex your wrist. If the nerve has been injured, you will be fitted with a wrist/hand splint and given exercises to help heal the condition. Ninety-five percent of patients who undergo treatment regain nerve function within six months. If the radial nerve loses function during manipulation or treatment, surgical exploration of the nerve and fracture site is indicated.
In most cases, your doctor will realign the broken bones without performing surgery. When surgery is required, nails or pins are used to hold the bone fragments together. Appropriate analgesia is used and outpatient pain medication is prescribed. Surgical risk increases with smoking and/or the use of drugs, including mind-altering drugs, muscle relaxants, antihypertensives, tranquilizers, sleep inducers, insulin, sedatives, beta-adrenergic blockers, and corticosteroids. Drink only minimal amounts of water before manipulation or surgery.
Depending on the type of fracture, the arm will be immobilized by means of one of the following:
- A hanging cast for fractures of the neck of the humerus. This cast is placed on the lower arm and provides weight to overcome muscle spasms so that the fractured bones can realign themselves.
- A shoulder-to-wrist rigid cast, used for uncomplicated shaft fractures.
- A splint covering the upper arm from the top of the shoulder to the elbow, with a supporting collar and cuff to enable the forearm and wrist to remain in a flexed position. After two weeks, this splint may be replaced with a humeral fracture brace, to be worn for at least 6 weeks or until there is radiographic evidence of healing. This brace also requires a sling to provide support to the flexed forearm and wrist.
To assure healing, follow the instructions given by your doctor. If possible, arrange your bed so that your upper body is elevated while you sleep. Some patients need to sleep in a chair. Eating highly nutritious foods promotes the healing process. Acetaminophen is useful for mild pain.
If a cast is not necessary, continue R.I.C.E. instructions for 48 hours after injury. After that time, hot baths, showers, whirlpools, compresses, heating ointments and liniments all increase blood circulation to the injury, ease discomfort, and help tissues heal. If a cast is prescribed, do not insert objects in the cast that cannot be removed. After the cast is removed, use frequent ice massage. Fill a large Styrofoam cup with water and freeze. Tear a small amount of foam from the top of the cup so the ice protrudes, and massage firmly over the injured area in a circle about the size of a baseball. Do this for 15 minutes at a time, 3 or 4 times a day.
Actively exercise all muscle groups that are not immobilized, as muscle contractions promote fracture realignment and hasten healing. Flexing and extending exercises for the wrist are also used to rehabilitate the arm. Once the splint is removed, range-of-motion exercises for the arm help recondition it. Resume normal activities gradually after treatment, remembering that complete healing may take weeks or even months, depending on the seriousness of the injury.
The average healing time for this fracture is 6 to 8 weeks. Healing is considered complete when there is no motion at the fracture site and x-rays reveal complete bone union.