The operation was a reverse total shoulder replacement. Now, shoulders are built pretty crappy. Four measly muscles support
the joint. Together they are called the rotator cuff, and they consist of the following muscles: supraspinatus, infraspinatus, subscapularis, and teres minor. These muscles can be damaged relatively easily, which can lead to any number of problems including pain, disuse, muscle atrophy, etc. These problems, when severe enough, warrant replacement of the joint.Typical shoulder replacement prostheses are modeled after
normal shoulder anatomy (ball and socket joint). The head of the humerus (the upper arm bone) is shaped like a sphere, and the scapula (the shoulder blade) has a spherical socket called the glenohumoral fossa.However, because of the damage to the rotator cuff, the deltoid muscle (located over top of the rotator cuff on the shoulder, now serve the purpose of stabilizing the joint. Because of the angles of pull, the deltoid doesn't do a very good job naturally at producing the complex movements of the shoulder.
So what's the solution? Flip it around. Hence, REVERSE total shoulder replacement. Now the deltoid has a mechanical advantage. Pictured below are the prostheses used for the operation.
The surgery was pretty cool to watch. I also had the opportunity to watch a knee arthroscopy and a carpal tunnel release surgery. More to come on those I'm sure, as I am finding ANY reason right now to put off my homework.
