intra-articular anatomy
Last reviewed 01/2018
The acromioclavicular joints are noted for the following intra-articular structures:
- articular surfaces:
- disposed anteriolaterally to posteromedial; hence a tendency for the clavicle to be displaced superiorly during dislocation
- covered in fibrocartilage
- slightly convex facet on lateral end of clavicle
- slightly concave facet on medial end of acromion
- joint capsule:
- lax, fibrous and attached to articular margins
- reinforced by:
- fibres of trapezius superiorly
- thickening of capsule superiorly and inferiorly - the acromioclavicular ligaments
- lined by synovial membrane
þþ a fibrocartilaginous disc is suspended from the superior part of the joint cavity
- wedge-shaped
- compensates for the slightly incongruous articular surfaces
- occasionally, it completely divides the joint into two separate synovial compartments akin the the sternoclavicular joint