This surgery removes the damaged or diseased ball end of the humerus bone and replaces it with an artificial joint that completely reverses the structure of the shoulder.
Entering the Joint
The surgeon makes a small incision into the shoulder and frees the head of the humerus bone from the socket. (The shoulder joint is a ball-and-socket joint.)
Unlike traditional shoulder replacement components, the implants used in this procedure will make the end of the humerus bone act like the socket and the glenoid labrum act like the ball. Reversing the joint helps compensate for loss of strength caused by damage to the rotator cuff.
Preparing the Humerus
First, the head of the humerus bone is safely cut at an angle and removed. The upper portion of the humerus is then hollowed out to receive the socket implant.
Implanting the Socket
The metal socket component is inserted into the end of the humerus. Bone cement may be used to secure the implant. The socket cup is attached to the top of the implant.
Preparing the Glenoid
The glenoid (shoulder socket) is reshaped, creating a stable surface to attach the metal ball component.
Implanting the Ball
The base of the ball component is anchored firmly with four screws. The ball is then screwed into the base.
End of Procedure
The humerus and glenoid components are put together to form the new joint. Instead of relying on the damaged rotator cuff muscles, patients will now use the stronger deltoid muscle to lift the arm.