In a traditional shoulder replacement, the ball of the shoulder is replaced with a metal ball and the socket is replaced with a plastic socket. The plastic socket is made of polyethylene. One of the current problems facing joint replacements is that the polyethylene can wear out over time. This is one reason why standard shoulder replacement are often not recommended for young patients.
One factor that contributes to Polyethylene wearing out is oxidation. It gets technical here, but for those who are interested in understanding this process further, please keep reading:
Oxidation can make polyethylene implants more brittle, more rigid and more fragile, causing the implant to wear faster and no longer withstand the normal joint forces the way it should and ultimately fail.
Oxidation of shoulder replacements has recently been in the news because of the recall affecting some Exactech shoulder replacement implants. This recall was due to an error with the packaging of their products. One of the layers in the packaging process was faulty, allowing for oxidation to occur prematurely. If you are interested in reading more about this recall listed on the FDA website click here, or specifically from the Exactech website, click here.
-Left Xray shows a failed aTSA due to oxidation of the polyethylene at less than 4 years from surgery; Right Xray showing same implant at two-week post-op.
The innovative Ream and Run shoulder replacement is an option that avoids the possible issues of a plastic socket wearing out and failing. This procedure can offer a better solution for young and active patients as there is no plastic socket inserted.
