A reverse shoulder replacement involves reversing the positions of the ball and socket in the shoulder joint. In this procedure, a metal ball implant is inserted into the patient’s natural socket, and a plastic socket implant is placed into the humeral head. This reverse configuration enhances stability as it doesn’t depend on tendons for support. Instead, the deltoid muscle, rather than the rotator cuff tendons, controls the motion. This makes it an excellent option for patients who need shoulder resurfacing but lack healthy soft tissues to maintain stability and movement. Patients with shoulder arthritis and significant rotator cuff tears are often ideal candidates for this procedure.

The rationale behind the reverse shoulder replacement is based on the natural anatomy of the shoulder. In a healthy shoulder, the ball rests against the socket rather than being deeply enclosed within it, as seen in the hip joint. The ball’s position relies on the surrounding tendons and socket for stability and movement. However, in certain types of arthritis, these tendons can be severely damaged, torn, or non-functional. In such cases, a typical shoulder replacement, which uses a ball implant, would not have the necessary soft tissue support for stability and movement.

Surgeons at HSS have been at the forefront of developing both traditional (also known as “anatomic”) and reverse shoulder replacements.