Although the AC joint is between the shoulder and the clavicle, it is considered an intermediate joint. If you look at the example intermediate joints in the descriptor for 20605 they include: temporomandibular, acromioclavicular, wrist, elbow or ankle, or olecranon bursa.
Joint pain can have causes that aren’t due to underlying disease. Examples include overuse such as heavy physical activity, lack of use, sprains, or strains.
