Expansion
A saddle-shaped synovial joint with an articular disc, the sole articulation of the limb with the trunk
Expansion
- The only bony articulation between the upper limb and the axial skeleton
- A saddle-shaped synovial joint between the medial clavicle, the manubrium and the first costal cartilage
- Divided into two cavities by a strong articular disc
- Stabilised by the anterior and posterior sternoclavicular, interclavicular and especially the costoclavicular ligaments
The disc is the key to its strength: it absorbs force transmitted along the clavicle and prevents the medial end riding up onto the manubrium.
Posterior dislocation is rare but dangerous, because the brachiocephalic vessels, the trachea and the oesophagus lie immediately behind. The medial clavicular epiphysis is also the last in the body to fuse, at around 25 years, which is used in forensic age estimation.