Anatomic shoulder replacement restores natural anatomy with a plastic ball on the humerus, relying on an intact rotator cuff for stability. Reverse replacement swaps the positions, placing the ball on the glenoid side instead, so the implant itself provides stability. Reverse is used when the rotator cuff is torn or damaged.
What's the difference between an anatomic and a reverse shoulder replacement? Well, both replacements have the goal of improving function and providing pain relief, but they work much differently. With an anatomic replacement, as the name sounds, the goal is to restore the anatomy. You place a ball on the ball side and a socket on the socket side. This is typically a plastic. The goal is to restore the anatomy to improve function, including range of motion, and to provide pain relief. This relies on the rotator cuff, which surrounds the ball and the socket joint, or the glenohumeral joint, in order to maintain stability. So you have to have an intact act rotator cuff. A reverse shoulder replacement does not rely upon the rotator cuff. A ball is placed on the socket side and a stem with a cup is placed on the arm bone side. So stability is provided by the structure of the joint or how it's designed. This is typically used with people with rotator cuff tears or in people who have arthritis where there's certain risks of the socket side loosening, particularly that plastic side being at higher risk of loosening over time. So both are intended to give pain relief and improve function, but they work much differently.
