Arthritis of the wrist can result from many causes. Sometimes, the wrist may become so painful that surgery is recommended to fuse the wrist. This is sometimes called an arthrodesis of the wrist.

Wrist fusion or arthrodesis eliminates pain by allowing the bones that make up the joint to grow together, or fuse, into one solid bone. The procedure involves a trade-off; it reduces pain, but also reduces the patient’s ability to move the joint. Fusions were very common before the invention of artificial implants for the replacement of arthritic joints and they are still very commonly used.

A wrist fusion is somewhat different from many fusions. Most joints are made up of only two bones that need to be fused. The wrist has many bones that must be fused together. The goal is to get the bone in the forearm, called the radius, to fuse into one long bone that connects the carpal bones of the wrist and the metacarpals of the hand.

With a fusion, the hand can still be turned palm up and palm down by rotating the forearm, but the wrist will not bend. While range of motion is limited, strength is enhanced and pain can be reduced significantly.

Regaining strength is especially important to young people who work with their hands doing labor-intensive activities. These patients need strength more than flexibility. The wrist fusion reduces pain and gives them a strong wrist that is good for gripping. Patients who need more movement than strength should consider another type of operation, such as an artificial wrist joint replacement.

Procedure

A wrist fusion begins by making an incision down the back of the wrist.

Since most of the blood vessels and nerves are on the other side of the wrist, this helps prevent damage to these structures. Most wrist-fusion operations use bone graft taken from the pelvic bone to help the wrist bones grow or fuse together, which requires incisions on the back of the wrist and a small incision over the pelvic bone.

Next, the tendons and ligaments on the back of the wrist joint are moved to the side to allow visibility of all the bones and joints of the wrist. The cartilage surface of each joint that is to be fused is removed, leaving many small bones with some space between them where the cartilage has been removed. The bone graft that has been taken from the pelvis is placed between each of the bones.

Next, a metal plate with screw holes is placed on the back of the wrist from the radius to the metacarpal bone of the long finger.

The metal plate is attached with metal screws to hold the bones in the proper alignment without moving while the bones grow together and fuse. The metal plate is not removed unless it causes problems.

At the end of the operation, the incisions are sutured together and the arm is placed in a large splint or cast.

Important Considerations for Patients

Complications from wrist fusion surgery include infection, nerve and blood vessel injury, and non-union.

Infection. Antibiotics are usually given before the operation to reduce the risk of infection. If an infection occurs, antibiotics may also be given to cure the infection. Additional operations may be necessary to drain the infection if it involves the area around the bone graft and metal plate.

Nerve and blood vessel injury. All of the nerves and blood vessels that go to the hand travel across the wrist joint. Because the operation is performed so close to these important structures, it is possible to injure nerves or the blood vessels during surgery. The result may be temporary if the nerves have been stretched by retractors holding them out of the way. It is not very common to have permanent injury to either the nerves or the blood vessels.

Non-union. Sometimes the bones do not fuse as planned. If the motion from a non-union continues to cause pain a second operation may be performed to complete the fusion. This usually means adding more bone graft and making sure that any plates or metal pins being used are holding the bones still to allow the fusion to occur.