Blue Boxes II Flashcards
paralysis of serratus anterior
- damage to long thoracic nerve (superficial to serratus anterior)
- causes winged scapula (medial border of scapula moved laterally and posteriorly
- unable to abduct limb above horizontal (serratus anterior is unable to rotate glenoid cavity of scapula superiorly, but trapezius (CN XI) aids in motion and is unaffected)
Thoracodorsal n. injury
C6-8
supplies latissimus dorsi
vulnerable in surgery in inferior axilla or mastectomy
causes inability to raise trunk w/ upper limbs (climbing) or use a crutch
^require active depression of scapula
Dorsal scapular nerve injury
Innervates rhomboids, damage causes scapula on affected side to sit farther from the midline than the unaffected side
Axillary nerve injury (C5-C6)
- passes inferior to humeral head around surgical neck, supplying deltoid, teres minor, and the long head of the triceps brachii
damaged by humeral head fracture OR glenohumeral dislocation
damage causes deltoid atrophy and loss of sensation in proximal, lateral arm due to damage to superior lateral brachial cutaneous n. (branch of axillary n.)
Scapular arterial anastomoses
Dorsal scapular a.
suprascapular a.
subscapular a. (via circumflex scapular a.)
subscapular a, receives blood from the suprascapular a., intercostal a., and dorsal scapular a. (via thoracodorsal a.) allowing collateral circulation to reach the 3rd part of the axillary a. during slow occlusion of the axillary a.
Sudden occlusion –> no time for the development of proper collateral circulation, causing arm, forearm, and hand ischemia
Ligation of brachial a.: (between subscapular a. and deep brachial a.) causes ischemia as above due to lack of collateral circulation
Enlargement of axillary lymph nodes
upper limb infection causing lymphangitis, usu at humeral nodes first
visible as warm, tender red streaks on skin of limb
cancer in apical nodes can cause adherence to axillary v. –> req excision. Enlargment of apical nodes may obstruct cephalic vein superior to pectoralis minor
brachial plexus injuries
damage to lateral cervical triangle in neck or to axilla causing partial/full paralysis and anesthesia
superior trunk injury (C5, C6)
damage from inc angle between neck and shoulder, such as falling on shoulder from a horse/motorcycle, causing avulsion of stretching of the superior roots of the brachial plexus
Erb’s palsy (waiter’s tip) - shoulder adducted, arm medially rotated, elbow extended
similar damage w/ shoulder dystocia (during birth) where shoulder is caught on pubic symphysis
Backpacker’s palsy –> shoulder spasms etc
injury to long thoracic n.
Paralysis of serratus anterior
inability to laterally rotate the inferior border of the scapula, preventing abduction (via superior movement of the glenohumeral fossa)
injury to Suprascapular n.
Paralysis of supraspinatus and infraspinatus, causing loss of abduction initiation and weakened lateral rotation. (But subscapularis is unaffected, allowing medial rotation.)
Musculocutaneous n.
paralysis of biceps brachia, brachialis, coricobrachialis causing weakened flexion at elbow
axillary n.
paralysis of deltoid and teres minor, prevents aBduction of upper limb
acute brachial plexus neuritis
idiopathic neuropathy
severe shoulder pain and inflammation proceeding a trauma or infection
cord compression
prolonged hyperabduction of the arm over the head (ceiling painting, etc) causing cord impingement between coracoid process and pectoralis minor tendon
–> radiculopathy down arm with parasthesia, erythema and hand weakness due to compression of axillary artery/vein and nerves
Klumpke’s Palsy (Inferior Trunk C8, T1)
Sudden pulling of upper limb superiorly can damage lower plexus nerve roots
Pulling of a newborn’s limb during birth causes similar damage.
^Both result in Claw Hand, or an inability to flex the small and ring fingers when attempting to make a fist, and weakness flexing the thumb, index and middle fingers