The sternoclavicular and acromioclavicular joints connect the clavicle to the sternum and scapula, respectively. Both joints contain articular cartilage and a fibrocartilaginous disc that divides the joint cavity. The sternoclavicular joint has three major ligaments and can dislocate. The acromioclavicular joint contains three ligaments and allows limited rotation and anteroposterior movement, with common injuries including dislocation, sprains, and fractures.

1. The sternoclavicular joint
&
The Acromioclavicular joint

2. The sternoclavicular joint
• The Sternoclavicular joint is a saddle type of
synovial joint between the sternal end of
clavicle & the manubrium of sternum with the
articulation of 1st costal cartilage.
• It is structurally classed as a synovial
saddle joint and functionally classed as a
diarthrosis and multiaxial joint.

4. Articular cartilage and Disc
The articular surfaces are covered with fibro-cartilage.
The joint is separated into two compartments by a
fibro-cartilaginous articular disc.

5. Ligaments of SC joint
• There are three major ligaments present in the
Sternoclavicular joint.
• Posterior and anterior sternoclavicular ligament.
• Interclavicular ligament.
• Costoclavicular ligament.

10. Dislocation of sternoclavicular joint

12. Acromioclavicular joint

13. The Acromioclavicular joint
• The Acromioclavicular (AC) joint is a plane type
of synovial joint taking place in between the
acromion of scapula and the clavicle.
• It has two atypical features :
• The articular surfaces of the joint are lined with
fibrocartilage (as opposed to hyaline cartilage).
• The joint cavity is partially divided by an
articular disc.

14. Features of Acromioclavicular joint
• Articular surface
• Articular disc & joint
cavity
• Fibrous capsule
• ligaments

15. The Acromioclavicular joint
• Ligaments :
• There are three major ligaments present in
the acromioclavicular joint.
• Acromioclavicular ligament
• Conoid ligament
• Trapezoid ligament

17. Neurovascular Supply –
• Vessels :
• The arterial supply to the joint is via two vessels.
• Suprascapular artery
• Thoraco-acromial artery
• Nerves :
• The acromioclavicular joint is innervated by
articular branches of the suprascapular and
lateral pectoral nerves. They both arise
directly from the brachial plexus.

18. • Movements of the joint
• The AC joint allows a degree of axial rotation
and anteroposterior movement.

21. • Injuries of the joint
• Dislocation of the clavicle
• Sprains
• Fractures
• Degenarative arthritis

22. Sprain of AC joint