Orthopedic Anatomy of the Shoulder

*only link from the upper extremity to the axial skeleton*middle 1/3 is most commonly fractured bone in the body (usually via a fall on the shoulder)*first bone to ossify, last bone to fuse

*posteriorly has supraspinous and infraspinous fossa*anteriorly is the corocoid process, glenoid and acromion

*pear shaped portion of the scapula*has an infraglenoid and supraglenoid tubercle*head of the humerus fits into the notch

Hook shaped lateral prominence of the scapula

*anatomical and surgical necks*greater and lesser tuberosities

Common fx site (especially in the elderly)

Fx's here have a high risk for osteonecrosis

Insertion sites for (SITS):*supraspinatus*infraspinatus*teres minor

Insertion sites for (SITS):*subscapularis

*usually via high-energy trauma *UNCOMMON (mostly seen in young males)

*usually via fall onto shoulder*aka "Shoulder Separation"

*MOST COMMON dislocation*common in young athletes*often associated with tuberosity of glenoid rim fxs*Anterior dislocation most common

*Hippocratic/traction*Stimson (weights)*Milch - traction at elbow with slow gradual external roation and ABduction of limb

1. Sternoclavicular joint2. Glenohumeral joint3. Acromioclavicular joint4. Scapulothoracic articulation* 2:1 ratio of glenohumeral joint to scapulothoracic articulation motion during shoulder ABduction*UNSTABLE joint

1. Sternoclavicular2. Costoclavicular3. Interclavicular