• posterior capsular ligament preserves anterior-posterior stability
• anterior sternoclavicular ligament prevents superior displacement of medial clavicle
• anterior part of costoclavicular ligament prevents superior rotation and lateral displacement
• posterior part of costoclavicular ligament prevents inferior rotation and medial displacement
• intra-articular disk ligament prevents medial displacement of clavicle
• Injuries are uncommon
• High velocity generally
• Anterior most common 3:1 to posterior
• Posterior needs CTA to assess vascular injuries
• Posterior impaction to shoulder results in posterior dislocation
IMAGING MRI useful Patients often already undergoing CT for other injuries under normal circumstances 50% of the clavicular head articulates with the manubrium. Comparison with the contralateral side useful but beware bilateral injuries Posterior dislocation requires vascular assessment ULTRASOUND Better for anterior dislocation Good for injecting joint