Shoulder joint replacement surgery (also called shoulder arthroplasty) is a great treatment for many people with shoulder pain from arthritis. But patients who don’t have enough muscle function to stabilize the joint may not be able to benefit from the traditional implant design — one that mimics the normal anatomic shoulder.
Instead, a different type of shoulder replacement, called reverse shoulder replacement has been developed. And it has worked so well, surgeons have expanded the number and types of patients who can qualify for this type. The reverse shoulder replacement does exactly as the name suggests: reverses the socket and the ball, placing the ball portion of the shoulder where the socket used to be and putting the socket where the ball or humeral head would normally be.
This new design gives a much more stable shoulder joint that can function without an intact rotator cuff. The artificial joint itself provides more stability by creating a deeper socket that prevents the ball from sliding up and down as the shoulder is raised. Shear forces are transformed into compressive forces.
This simple change allows the large deltoid muscle that covers the shoulder to lift the arm. The result is a shoulder that functions better, is less painful, and can last for years without loosening. Early studies have reported very favorable results — enough so that surgeons have expanded the number and types of patients who can benefit from this procedure.
Reverse shoulder replacement was only approved by the US Food and Drug Administration in 2004, so it is quite new. Some surgeons used them as early as 1998 when they first came out as a customized implant. European surgeons have been using them much longer with very good results. So finding someone with more experience than your surgeon may not be possible.