40. Dislocation of the shoulder joint

General information

• One of the most frequent luxations of the musculoskeletal system
• Roughly 40% of all luxations are shoulder dislocations
• Factors causing dislocation:
• The articular fossa of the scapula is shallow and small and the head of the humerus is too large
• The ligament apparatus and articular capsule are relatively weak and relaxed
• The shoulder joint has great range of motion

Etiology (mechanisms)

• Indirect lever-like- fall over the posteriorly abducted arm
• During fall, long arm pushes the head in the anteroinferior section of joint
• Head of humerus ruptures or detaches from the articular capsule

Classification of luxations of the shoulder

• Anterior- most frequent
• Superior- very rare
• Posterior- very rare
• Inferior- second most common

Symptoms

• Typical deformity- acromion protrudes out and epaulet symptom is positive
• Shoulder loses oval shape
• Spring resistance
• Head of humerus could be visible or be palpated
• Limb stays in forces position
• Patient holds affected arm with the healthy one
• Head tilted towards luxated shoulder
• Arm and shoulder appear shortened
• Movements of joint very limited
• Severe pain
• Edema