Reverse Shoulder Replacement: How It Works & What to Expect

So I'll start off briefly with the history.

The concept of the reverse shoulder arthroplasty, you've got a ball, you've got a socket, we flip them.

Where the socket used to be, we put a ball.

Where the ball used to be, we put a socket.

But why? Well, there's a number of reasons for that.

The biggest reason is that you have lost stability of a shallow socket because your rotator cuff's gone.

That's the most common reason.

So that ball's just moving around because there's no constraint because your rotator cuff's torn.

By putting on a new ball and a deeper socket, you make a more constrained joint, but you also lengthen the arm to make the deltoid more tensioned and giving a mechanical advantage to constrain that joint more firmly.

That's probably the most succinct way I can explain it.

It's for those two reasons.

You can get more into deltoid wrap effect, lateralization, and distalization, and we'll get into that a little bit, but that's the biggest reason that that works.

So I'll go even simpler because I'll translate it to redneck for you.

We try to make it so the deltoid can do the job of the other muscles that don't want to do their job anymore.

That would be my way to redneck it.

That's a great way to put it.

And this concept existed in the 70s, but it failed, mostly for mechanical reasons.

The fixation of the metal into the bone was too fragile.

It was too much force on that interface, and so they failed.

And so most people in the United States just gave up on the idea.

It's like, this is impossible.

We can't do it.

And then there was a guy named Gramont in France in the 80s who came up with a novel design that took a little bit more tension off that lateralized construct, and the two implants weren't totally linked.

They were sort of loosely linked, or I'd call it partially constrained.

And that led to some success.