Upper Extremity

The clavicle is a bone of the upper extremity which is commonly fractured – often by a fall on an outstretched arm and hand, a fall on the point of the shoulder, or a direct blow to the clavicle.

a The fracture site is most commonly observed in the middle ⅓ of the bone – a region of transition between the concave and convex orientation of the bone.

b On clinical examination, the region demonstrates marked deformity and swelling, and the patient is often unable to support the weight of the affected limb. Beyond this, physical examination of the region should be used to help rule out lesions of underlying structures such as the subclavian artery, brachial plexus, and superior lobe of the lung.

c A/P radiograph of the shoulder girdle ( Fig. 5.19 ) allows the location and extent of the fracture to be easily visualized.

a [ L231 ], b [ G721 ], c [ G305 ]

The position of the scapulae on the posterior thorax allows one to quickly approximate the level of the thoracic vertebrae during clinical examination. The T3 vertebra is intersected by a line that connects the root of the spines of the left and right scapulae. A line that connects the inferior angles of the left and right scapulae also intersects the vertebral column at the T7 level.

[ L126 ]

Humeral fractures ar e classified by their location (proximal end/mid-shaft/distal end).

a Proximal fractures commonly occur in the region of the surgical neck, and can result in lesions of the axillary nerve. The ‘NEER classification’ system is often used to describe proximal humeral fractures according to:

• 1.

  number of fractured pieces,

• 2.

  degree of displacement of the fractured bone.

b A midshaft fracture can be associated with damage to the radial nerve as it courses distally within its groove on the posterior aspect of the shaft of humerus. Radial nerve injury will impair function of muscles on the posterior forearm which power wrist extension, and will result in a ‘wrist drop’ deformity. In addition, a sensory deficit may occur on the posterior aspect of the forearm, in the first interdigital space (autonomic region) of the hand, and on the posterior surfaces of fingers 2 through 4.

a [ R234 ], b [ E402 ]

a While the strong ligamentous support of the S/C joint make it very stable, dislocations can occur as a result of significant direct or indirect force to the shoulder.

b A posterior dislocation has the potential to result in life threatening complications due to the proximity of the joint to the lung, trachea, key neurovascular structures, and the esophagus.

a [ L126 ], b [ H064-001 ]

a Injury or displacement of the A/C joint is referred to as a ‘shoulder separation’. The extent of clavicular displacement is used to classify the injury as mild/moderate/severe. In a mild injury, the acromioclavicular ligament is injured. In a moderate injury, the acromioclavicular ligament is completely disrupted, and the coracoclavicular ligament is damaged. With a severe injury, the acromioclavicular and coracoclavicular ligaments are both severly damaged.

b A/C joint separations can be easily identified because of the high riding clavicle which is visible on A/P radiograph. In general, the more severe the A/C joint injury, the further the lateral end of the clavicle is displaced. a [ L126 ], b [ G718 ]

a Dislocation of the G/H joint is a frequent injury of the shoulder girdle . The joint is prone to injury because of the weak bony and ligamentous support which guides movements of the head of humerus on the smaller glenoid fossa. G/H joint dislocations most frequently occur in an anterior and inferior direction and result in the head of humerus being positioned inferior to the coracoid process in the subcoracoid region.

b On examination, the contour (or dome appearance) of the shoulder is reduced and the arm appears longer.

a [ R234 ], b [ E748 ]

Impairment of normal scapulohumeral motion can lead to alterations in the subacromial space and degenerative changes in structures such as the supraspinatus tendon which passes through the subacromial space (identified by the white arrow in the A/P radiograph). As a result, patients experience pain when lifting the arm overhead because this movement results in compression of the supraspinatus tendon underneath the acromion of the scapula (i.e. the roof of the shoulder). This phenomenon is commonly referred to as shoulder impingement syndrome.

a [ G217 ], b [ L126 ]

An angiogram of the axillary region of the shoulder can be used to visualize the different branches of the axillary artery. The coracoid process serves as a key visual landmark for orienting oneself to the three sections of the axillary artery, as it represents the superior attachment for the pectoralis minor.

[ H063-001 ]