From the Research
The acromioclavicular (AC) joint is a small, synovial joint located at the top of the shoulder where the acromion process of the scapula meets the lateral end of the clavicle (collarbone), typically measuring about 9-19 mm in width and 3-5 mm in depth. The AC joint is classified as a plane or gliding joint, though these dimensions can vary among individuals. The AC joint is stabilized by several ligaments, including the acromioclavicular ligament and the coracoclavicular ligaments. This joint plays an important role in shoulder function by allowing the scapula to rotate and tilt during arm movements, particularly when raising the arm above shoulder height. The small size of the AC joint makes it susceptible to injury, particularly from direct trauma to the shoulder, which can result in sprains or separations of varying severity. Understanding the size and structure of the AC joint is essential for properly diagnosing and treating shoulder conditions that affect this area, as noted in studies such as 1. Some studies, like 2, have investigated the treatment of AC joint injuries, but the size of the joint itself is not directly addressed in these studies. However, the anatomy of the AC joint is discussed in detail in studies like 3, which highlights the importance of understanding the joint's structure in diagnosing and treating injuries. Overall, the size of the AC joint is an important consideration in the diagnosis and treatment of shoulder conditions, and its small size makes it susceptible to injury. Key points to consider when evaluating the AC joint include:
- The joint's location at the top of the shoulder
- Its classification as a plane or gliding joint
- The ligaments that stabilize the joint, including the acromioclavicular ligament and the coracoclavicular ligaments
- The joint's role in shoulder function and its susceptibility to injury, as discussed in studies like 4 and 5.