Scapular/Shoulder Region Flashcards
The Shoulder Girdle consists of
Scapula, coracoid process, sternal process, manubrium, greater tubercle, lesser tubercle
Sternoclavicular articulation
Synovial, saddle
Acromioclavicular articulation
Synovial, plane
Glenohumeral articulation
Synovial, ball/socket
Bony landmarks of humerus
Capitulum, trochlea, surgical neck, anatomical neck, greater tubercle, lesser tubercle, intertubercular sulcus
What is the acromioclavicular joint reinforced by?
Acromioclavicular ligament and coracoclavicular ligament (trapezoid and conoid ligaments)
Movements of the glenohumeral joint
Flexion, extension, medial rotation, lateral rotation, adduction, abduction, circumduction (F, E, AD, AB)
What does the synovial sheath wrap around?
Tendon of long head of biceps brachii
What is the biceps tendon held in place by?
Transverse humeral ligament on supraglenoid tubercle
What does the biceps tendon + transverse humeral ligament form?
Joint capsule
Trapezius innervation, attachment, function
Innervation: spinal accessory nerve
Attachment: upper nuchal line, clavicle
Function: depress, abduct, elevate
Latissimus dorsi innervation, attachment, and function
Innervation: thoracodorsal nerve
A: intertubercular sulcus
F: medially rotate, extend, adduct
Deltoid innervation, function, testing
Innervation: axillary nerve
Function: medially rotate
Testing: abduct against resistance
Rotator cuff muscles
Supraspinatus, infraspinatus, teres minor, subscapularis
Most commonly injured rotator cuff muscle
Supraspinatus
Separation (AC joint dislocation)
Involves injury to AC joint, complete separation involves rupture of acromioclavicular and coracoclavicular ligaments
Bursitis
inflammation of subdeltoid or subacromial bursa
What can be torn when trying to carry too much?
Supraspinatus tendon
Drop arm test
ask patient to lower arm from 90 degrees of abduction; failure to lower the arm in a smooth, controlled fashion or with pain suggests a tear of the supraspinatus tendon
What does a dislocation of glenohumeral joint sacrifice?
Stability of the joint
Most shoulder dislocations occur…
Anteriorly, anterior inferior
Anterior dislocation (95%) description
Often tears joint capsule, and detaches labrum, can result in a compression fracture of the humeral head, may injure axillary or radial nerve or compress axillary artery
Posterior dislocation description
Can compress posterior circumflex humeral artery
What are infraspinatus and supraspinatus innervated by
Suprascapular nerve
Teres minor is innervated by
Axillary nerve
Subscapularis innervation by
Upper subscapular nerve
Levator scapule and rhomboids function and innervation
Innervation: dorsal scapular nerve
Function: retracts and elevates scapula
Serratus anterior function, innervation, testing
Function: protraction of scapula (raise your hands)
Innervation: long thoracic nerve
Testing: abduct hand, push against wall
What can damage long thoracic nerve?
Mastectomy
Triangular space borders
Superior: teres minor
Inferior: teres major
Lateral: long head of triceps brachii
Quadrangular space borders
Superior: teres minor
Inferior: teres major
Medial: long head of triceps brachii
Lateral: humerus
Triangular interval
Superior: teres major
Medial: long head of triceps brachii
Lateral: humerus
What is inside triangular space?
Circumflex scapular artery
What does the circumflex scapular artery anastomose with?
Superficial circumflex artery
Quadrangular space contains…
Axillary nerve
Posterior circumflex humeral artery
Triangular interval contains…
Radial nerve
Profunda brachii artery
Vasculature of shoulder/scapula
Thyrocervical trunk -> transverse or superficial cervical artery, suprascapular
Axillary artery
Brachial artery -> profunda brachii
Axillary artery is divided by
Pectoralis minor!
Axillary artery part one
Superior thoracic artery
Axillary artery part 2
Thoracromial trunk, lateral thoracic artery
What is buddy buddy with the lateral thoracic artery?
Long thoracic nerve
Axillary artery part 3
Posterior circumflex humeral artery, anterior circumflex humeral artery, subscapular artery
Ligation of axillary artery between the thyrocervical trunk and subscapular artery will maintain
Collateral bloodflow to the UE via the scapular collateral network
Compression site for axillary artery
Anterior to teres major, proximal humerus
Axillary vein laceration
The cephalic vein MUST BE preserved as it becomes the only vein returning blood to UE
If penetrating trauma occurs on axillary vein, risk of
Air embolism
Spinal nerves of axillary nerve
C5 - C6
Fracture of surgical neck of humerus impacts
Axillary nerve, posterior circumflex humeral artery
Nerve injured with shaft of humerus
Radial nerve
Nerve injured with fracture with medial humeral epicondyle
Ulnar nerve
What muscles are innervated by axillary nerve
Deltoid and teres minor
What initiates abduction of arm?
Supraspinatus muscle
What tendon goes through shoulder joint
Long head of biceps
Most commonly fractured bone in UE
Clavicle
Chief flexor/extensor of shoulder joint
Deltoid
What can cause winged scapula?
Long thoracic nerve, spinal accessory nerve, dorsal scapular nerve
Risk of injury during clavicle fracture
Suprascapular VAN -> supraclavicular nerves, brachial plexus, subclavian vein
Dorsal scapular nerve (C4-C5) injury causes
Entrapment as it passes through the middle scalene muscle; injury results in a partially protracted scapula; weakness in elevation and retraction
Suprascapular nerve (C5-C6) injury
Injury at the suprascapular notch, clavicle fracture = weakness/atrophy of the supraspinatus and infraspinatus muscles
Thoracodorsal (C5-C6) nerve
• In danger during mastectomy, axillary lymph node dissection or trauma to axilla
• Paralysis of latissimus dorsi - weakness in adduction/extension/medial rotation of humerus
