Wrist Replacement

Definition

Wrist replacement surgery is performed to replace a wrist injured or damaged beyond repair. An artificial wrist joint replacement is implanted.


Purpose

Traumatic injuries or severe degenerative diseases affecting the wrist (such as osteoarthritis and rheumatoid arthritis with bony destruction) may require replacement of the painful wrist joint with an artificial wrist joint. The purpose of wrist replacement surgery is to restore wrist motion for activities of daily living and non-contact sports. A wrist replacement recovers lost strength by restoring length to the muscles and tendons of the fingers and wrist, maintains a useful arc of motion and provides the stability required for an active life.


Description

Surgery to replace a wrist starts with an incision through the skin on the back of the wrist. The surgeon then moves the tendons extending over the back of the wrist out of the way to access the joint capsule on the back of the wrist joint, which is then opened to expose the wrist joint area. A portion of the carpal bones and the end of the radius and ulna are then removed from the wrist to allow room for the new artificial wrist joint. The bones of the hand and the radius bone of the forearm are prepared with the use of special instruments to form holes in the bones; the stems of the artificial joint components can then fit in. Next, the components are inserted into the holes. After obtaining a proper fit, the surgeon verifies the range of motion of the joint to ensure that it moves correctly. Finally, the surgeon cements the two sides of the joint and replaces the tendons back into their proper position before closing the wound.

A total wrist replacement implant consists of the following components:

  • An ellipsoid head that simulates the curvature of the natural wrist joint and allows for a functional range of motion. This ensures that the patient may flex and extend the wrist and move it side-to-side.
  • An offset radial stem that anchors the implant in the forearm. The special shape of this component is designed to assist the function of the tendons used to extend the wrist and to ensure the stability of the implant.
  • An elongated radial tray surface with a molded bearing usually made of polyethylene. This component is required to distribute forces over the entire surface of the artificial joint.
  • A fixation stem that is secured to the patient's bone to add stability and eliminate rotation of the artificial joint within the bone.
  • A curved metacarpal stem that secures the artificial wrist within the hand.

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