If your shoulder has ever felt like it shifted partially out of the joint and then moved back into place, you may have wondered whether that counts as a dislocation or something else entirely. Yes, a shoulder can partially dislocate, and it’s more common than most people think.
What Is a Partial Shoulder Dislocation?
A partial dislocation of the shoulder is called a subluxation. This happens when the humerus (upper arm bone) slips partially out of the shoulder socket.
A full dislocation takes place when the ball pops out of the socket and doesn’t go back in until someone puts it back. A subluxation occurs when the joint slips out of position and then back into position by itself, sometimes so quickly that the individual is hardly aware that anything happened.
Both are types of shoulder instability, but they are different in severity and cause.
What Does a Subluxation Feel Like?
Symptoms can vary significantly from person to person. Some people feel a distinct pop or clunk as the shoulder slips and returns. Others describe it as a feeling of the shoulder giving way or going dead for a moment.
Some people get a sharp pain, others have more of a dull ache afterward, with temporary weakness of the arm. A common description is what athletes call a stinger or dead arm, a brief episode where the shoulder feels like it has shifted and the arm goes numb or weak for a few seconds before returning to normal. This can happen in contact sports or any activity that puts sudden force on the shoulder.
What Causes Shoulder Subluxations?
Some of the more common causes of shoulder subluxation include:
- Trauma: A subluxation can occur in a game when the shoulder receives a powerful blow or any impact that forces the shoulder into an unusual posture. It is like a complete dislocation, just with a little less power or at a slightly different angle.
- Repetitive Overhead Activity: Swimmers and anyone who uses the shoulder in overhead positions repeatedly can stretch out the ligaments and capsule around the joint over time. This looseness allows the ball to move more than it should.
- Ligament Laxity: Some people are more flexible than others and have looser joints, in general. This general looseness can give the shoulder an increased tendency to sublux without any specific injury.
- Previous Full Dislocation: If the shoulder has been fully dislocated, the tissues that hold it in place are often stretched or torn. This results in a less stable shoulder joint and an increased risk of future instability episodes.
Is a Subluxation as Serious as a Full Dislocation?
Not always, but it can’t be ignored. A single subluxation following a traumatic event may resolve without any long-term issues. But repeated subluxations indicate something isn’t working right in the shoulder.
Over time, that instability can lead to progressive damage to the cartilage, labrum, and other structures around the joint. The problem with ignoring recurrent subluxations is that the shoulder tends to get looser with each episode. Repeated instability episodes can become a bigger instability problem that may require surgery to fix.
Wrapping Up
If you’ve ever felt like your shoulder popped out of place, it’s worth having it checked out, even if everything seemed fine afterward. An orthopedic surgeon can take a deeper look at what is happening in the joint and determine whether it was a one-time event or something that needs attention.
Consult our board-certified orthopedic surgeon, Dr. Mufaddal Gombera, MD, for shoulder injuries. Call us today to book your appointment.
