Why A Sling For Six Weeks? PO Day 60

In the case of the reverse Total Shoulder Replacement (abbreviated rTSR) the ball and the socket are not attached to each other. They nest together, the ball screwed to the scapula and the cup at the top of the stainless steel post fitted into the humerus. This arrangement is the reverse of the natural shoulder joint, hence the name. The rTSR procedure is used when there is not enough of the rotator cuff intact to support the artificial device that normally would replace the cup in Total Shoulder Replacement arthroplasty.

This unusual reverse arrangement makes one somewhat more likely to dislocate the artificial joint. We human beings tend to get in some pretty weird positions. An unreachable itch in the middle of your back, a stuck zipper when you're trying to get out of a tight dress, or an angry wasp between your shoulder blades can lead to disaster. As my therapist says, extension, adduction and internal rotation is a dangerous combination. Catchy phrase.

Immobilizing the joint in the immediate weeks post op allows bone and tissue to grow into the prosthetic parts and better stabilize the joint. Conservative doctors, like mine, advise a solid six weeks wearing the sling 24 hours a day, 7 days a week. That's no guarantee that you can't or won't have trouble but it makes for a better start. This also explains the uber conservative approach to physical therapy in the first six weeks. The PROM (passive range of motion) technique administered by an experienced therapist allows the arm to be moved without interfering with the "knitting together" that is going on.

I've copied this photo of two x-rays showing the unfortunate process of a dislocation. The simplest fix involves manipulating the shoulder to get the the ball and joint realigned properly and then immobilizing the arm, either in a sling or even a cast, for up to six weeks. That must be the magic number.