A Rare Case of Posterior Injury to the Sternoclavicluar Joint
Earlier this month, Kevin Pillar of the Toronto Blue Jays sustained a disruption to the sternoclavicular (SC) joint of the right chest. This is an interesting case because a (SC) joint injury is a rare occurrence and even more so in the sport of baseball. If you analyze the video below, you will see he catches the ball with his left arm but braces his fall with his right causing the subsequent injury. It is crazy to think of how many dives we see throughout a season and rarely, if ever, is this type of injury seen. It also looks like the medical team did a great job diagnosing the injury and getting him immediate care. Let’s take a deeper look at what actually happened and why this injury can be so dangerous.
Anatomy of the Injury
The sternoclavicular joint is the connection between the clavicle and the breastbone, also known as the sternum. The sternoclavicular joint is stabilized by several different ligaments including the sternoclavicular ligament as well as the costoclavicular ligament, which connects the first rib to the clavicle. There are several different injuries that can occur to the sternoclavicluar ligament including a sprain, subluxation or dislocation. To clarify, a sprain would be stretching or tearing of the ligaments yet the joint is still intact, a subluxation would be when the clavicle separates from the sternum and is partially out of place, and a dislocation would be when the clavicle completely separates from the sternum and is completely out of place. When there is a subluxation or dislocation the most common type is an anterior injury. The clavicle bone is pushed outward away from the body. On the other hand, a more concerning injury would be if the clavicle is pushed inward, which is called a posterior injury.
Sternoclvaicular Joint (ZOOMED)
Evaluation of the Athlete
In general, an SC sprain will present with tenderness to palpation at the SC joint with associated swelling. The athlete may have pain with lifting the arm up overhead or across the body. There are several key findings that can indicate a dislocation. The pain is usually much more severe with a dislocation. In my experience, I have seen that is it very difficult to feel that the clavicle is out of place as there is significant swelling and the athlete does not want to be touched at all in this area. If an athlete refuses to let you examine the SC joint due to pain, I would have a high suspicion of a dislocation. Additionally, if the dislocation is posterior, athletes may present with shortness of breath, difficulty swallowing or numbness and tingling in the extremity. These symptoms are due to the direct compression of the trachea, esophagus or vascular structures in the neck. When a posterior dislocation is being considered it needs to be evaluated immediately. My suspicion is that Pillar likely was in severe pain and complaining of difficulty swallowing and was transported immediately for that reason.
In evaluating the injury x-rays are usually performed, but can be very difficult to interpret. In the cases I have seen, the best test is to obtain a CT scan to see a three dimensional view of the joint to better understand the positioning of the bone and if any compression is occurring.
CT Scan - Posterior Dislocation
Note the proximity of the clavicle that is displaced posteriorly to the trachea and the lungs.
Treatment of Sternoclavicluar Injury
If the diagnosis is considered a sprain or anterior subluxation usually the patient is treated with a sling for 4-6 weeks similar to the treatment of an acromiclavicluar injury. When a dislocation is discovered usually the treatment is to undergo surgery to place the clavicle back in to the joint with appropriate alignment.