On April 23rd, UFC lightweight fighter Joe Proctor had surgery on his shoulder. He tweeted a post-operative picture that date, indicating that the surgery went well. He had previously injured the shoulder in training and was pulled from his bout scheduled for UFC 159. Little was known about the surgery until earlier this month, when he tweeted the following.
@scottyeadon I got stability shoulder surgery— Joe Proctor (@JoeProctor) May 4, 2013
This tweet suggests that shoulder instability was the reason behind the surgery. When the shoulder is unstable, the head of the humerus bone can slip in and out of the socket. This occurs when the capsule and ligaments that provide stability to the shoulder joint become loose or torn. It is unusual for someone to have surgery after a single episode of shoulder dislocation, so if Proctor's surgery was indeed performed to correct an unstable shoulder, he has probably had repeated episodes of instability. A chronically unstable shoulder would be incompatible with successful combat sport competition at an elite level. Surgery to stabilize the shoulder can be done arthroscopically (or minimally invasive). While I do not know if this is the type of surgery that Proctor had, here is a good video showing such a procedure for an unstable shoulder.
The rotator cuff muscles are the critical dynamic stabilizers of the shoulder. These muscles work in conjunction with the shoulder joint ligaments to stabilize the extremely mobile shoulder joint. As Proctor recovers from the surgery, he will ultimately have to work on rebuilding proprioception of the shoulder joint. Proprioception refers to the body's ability to sense movement within joints, and to sense joint position. The proprioceptive system is made up of special nerves in the muscles, capsule and ligaments around joints. These "receptor" nerves can sense tension and stretch, and pass this information to the brain for processing. The brain then signals the muscles surrounding a joint to contract or relax in order to produce the desired movement. I have previously posted on the concept of proprioception as it relates to the shoulder. That can be found at the MMA Injury blog.