Complications

What are the potential complications of this fracture?

Nonunion and malunion are common complications of this fracture but compartment syndrome does occur and has severe consequences.

Compartment Syndrome

The muscles of the forearm move the hand and fingers. When a fracture occurs the bone and muscle bleeds into the closed muscle compartments of the forearm. In some cases this is enough to raise the intra-compartment pressure high enough to stop blood flow to the muscle. As a result the muscle fibers may swell up and die (called necrosis). The swelling increases the pressure to cause a vicious cycle that may end in extensive damage to the muscles of the forearm. This condition is called a compartment syndrome. Untreated, this results in shortening and scarring of the muscles and loss of finger movement. The result is sometimes referred to as a claw hand, because the hand assumes the shape of a claw.

The cardinal sign of compartment syndrome is pain and tenderness of the forearm increased by pressure and by movement of the fingers. Since it is normal for the forearm to hurt after a fracture or after surgery it is often quite difficult to diagnose compartment syndrome.

Doctors and nurses pay a lot of attention to this problem and maintain a high index of suspicion. The treatment for compartment syndrome is immediate surgery to open up the muscle compartments and relieve the pressure. If this is done before any die off of the muscle fibers the outcome is satisfactory although the skin wound may be quite dramatic. Otherwise the outcome depends on the amount of muscle necrosis that has occurred.

Malunion

If the bones of the forearm heal with angulation, shortening, or rotation the fracture is said to be malunited. This is referred to as a malunion. The deformity may be significant enough to prevent full rotation of the forearm or it may be unsightly. Loss of rotation causes a problem with normal hand function so this problem usually requires treatment. The healed fracture is cut and the bone restored to normal length, rotation, and bowing.

Sometimes the extra bone laid down as part of the healing process causes a bony block which interferes with movement of the forearm and it has to be removed. In rare cases the radius actually heals to the ulna (this is called a cross union) and this completely prevents rotation of the forearm. Once the normal shape of the bone has been restored by surgery the fragments are fixed with internal fixation. Early movement to maintain the motion achieved by surgery is recommended.

Closed reduction may not result in anatomical alignment of the bones. Malunion is less common after operative treatment for two reasons. The first is that one aim of surgery is to restore normal alignment of the bones and this aim is usually achieved. The second is that the patient is encouraged to move the forearm once it has been fixed and this reduces the chances of cross-union or the development of a bony block.

Nonunion

A nonunion occurs when the healing process does not go on to completion. The first stage of healing results in scar tissue developing in the gap between the bone fragments and this normally turns to bone. If the gap is too big or there is significant movement at the site bone development may not occur and it stays as scar tissue (called soft callus). This failure of healing is also affected by the blood supply of the area and such general medical factors as smoking, diabetes, and alcoholism.

Diagnosis of nonunion is a judgment call by the orthopaedic surgeon. In his/her judgement the fracture will not heal without intervention. The treatment depends on the circumstances but the principle is to do surgery to freshen the bone ends, immobilize them and improve the biological environment by using bone graft to stimulate healing.

Nonunion is more common after nonoperative treatment. It is painful to put stress on an nonunited fracture so treatment is usually continued until healing has been accomplished. The long term consequence of multiple procedures to achieve healing may be scarring and loss of function of the forearm muscles with stiffness.

Painful Hardware

The plates and screws used to immobilize the fracture fragments may be tender. Sometimes they can be felt under the muscle layers and are sore when you rest your arm on a table. Very commonly there is a persistent ache which may be increased by weather changes. The reasons for this symptom are not known but removal of the hardware eliminates the problem.

Surgery to remove the plates and screws is often done once the bones have healed. However, there is a well recognized risk of refracture in the first few weeks after plate removal and patients are advised to be protective of their arm during this period.

Infection

After an open fracture or less commonly after surgery the wound may develop a bacterial infection. This results in increased pain, redness and swelling of the wound area with drainage of pus developing later. Early recognition and treatment of a wound infection may prevent it from becoming established and infecting the bone. Bone infection hinders healing and may be difficult to eliminate.

Treatment requires long term use of antibiotics and surgery to remove all dead and contaminated tissue. The fixation is often left in so that the bone heals more quickly but hardware removal after healing is often required to finally eliminate the infection. With early aggressive treatment of infections the outcome is quite favorable.