Shoulder Anatomy

Front 1

List the ossification center, ossification age, and fusion age for the ossification centers of the scapula (1 primary, 6 secondary)

Back 1

CENTER OSSIFICATION FUSION
Body (primary) 8 wk (fetal) 15-20 yr (all)

6 Secondary:
Coracoid (tip) 1 yr
Coracoid 15 yr
Acromion tip 15 yr
Acromion 16 yr
Inferior angle 16 yr
Medial border 16 yr

Front 2

List the ossification center, ossification age, and fusion age for the ossification centers of the clavicle (3)

Back 2

CENTER OSSIFIES FUSES
Primary:
Medial & lateral 5 wk (fetal) 25 yr

Secondary:
Sternal 18 yr 25

Front 3

What is the term for failure of union between the acromian tip and remainder of the acromion?

Back 3

Os Acromiale

Front 4

List the ossification center, ossification age, and fusion age for the ossification centers of the Humerus

Back 4

CENTER OSSIFIES FUSES
Body (primary) 8 wk (fetal) Blends @ 6 yr unites _ @ 20 yr
Head 1 yr
Greater tuberosity 3 yr
Lesser tuberosity 5 yr
Capitulum 2 yr Blends unites w/ body at 16-18
Med epicondyles 5 yr
Trochlea 9 yr
Lat epicondyles 13 yr

Front 5

What are the 17 muscles that attach to the scapula?

Back 5

Omohyoid, Supraspinatus, Infraspinatus, Rhomboid Major, Rhomboid Minor, Teres Major, Teres Minor, Pec Minor, Biceps, Triceps, Coracobrachialis, Latissimus, Trapezius, Deltoid, Levator scapula, subscapularis, serratus anterior

Front 6

Is the glenoid retroverted or anteverted and to what degree?

Back 6

Retroverted approximately 5 degrees

Front 7

What are the 4 ligaments that attach to the scapula

Back 7

SGHL, MGHL, IGHL

Front 8

What 5 structures attach to the coracoid?

Back 8

Coracoacromial ligament, coracoclavicular ligaments (conoid (medial) and trapezoid (lateral)), conjoined tendon (formed by coracobrachialis and short head of biceps), and pectoralis minor

Front 9

What separates the suprascapular artery from the suprascapular nerve?

Back 9

Suprascapular notch has the superior transverse scapular ligament separating the suprascapular artery (superior) from the suprascapular nerve (inferior).

Front 10

How might atrophy of the infraspinatus be caused at the spinoglenoid notch?

Back 10

Usually labral disease causing compression of the suprascapular nerve at the spinoglenoid notch

At the spinoglenoid notch, the suprascapuloar artery and nerve are both inferior to the inferior transverse scapular ligament

Front 11

What is unique about the ossification and fusion of the clavicle?

Back 11

Is the the first bone to ossify (5 weeks of gestation) and the last to fuse (at the medial epiphysis at 25 years of age)

Front 12

What are the major and minor articulations of the shoulder?

Back 12

One major: Glenohumeral Joint

3 minor: Sternoclavicular, acromioclavicular, scapulothoracic

Front 13

What are the 5 static restraints of the shoulder?

Back 13

The articular anatomy, glenoid, labrum, negative pressure, capsule, and GH ligaments.

Front 14

What are the dynamic restraints of the shoulder?

Back 14

The rotator cuff, biceps tendon, periscapular muscles, proprioception

Front 15

What ligaments make up the sternoclavicular joint (4)?

Back 15

Anterior and posterior sternoclavicular ligaments, an interclavicular ligament, and a costoclavicular ligament.

Front 16

How much does the SC joint rotate with shoulder motion?

Back 16

30 degrees

Front 17

What is the difference in the types of motion of the AC and SC joints?

Back 17

SC is double-gliding with an articular disc
AC is plane/gliding with a fibrocartilaginous disc

Front 18

Is the scapulothoracic articulation a true joint? What is the ratio comparison of glenohumeral motion with scapulothoracic motion with abduction?

Back 18

No, it is not a true joint. The ratio is 2:1 (GH:scapulothoracic)

Front 19

What ligament is found at the spinoglenoid notch and what is the relationship of the suprascapular artery and nerve at this location?

Back 19

The inferior transverse scapular ligament; the artery and nerve are both inferior to the ligament

Front 20

What structure is important for superoanterior restraint in rotator cuff deficiencies?

Back 20

The coracoacromial ligament is important for superoanterior restraint in rotator cuff deficiencies and should be preserved during débridement of painful massive rotator cuff tears that cannot be surgically repaired.

Front 21

What is the function of the rotator cuff muscles and where do they attach?

Back 21

The rotator cuff muscles depress and stabilize the humeral head against the glenoid; all attach to the greater tuberosity except the subscapularis, which has a lesser tuberosity insertion (shoulder internal rotator).

Front 22

Which muscles are stronger in the shoulder, the internal rotators or the external rotators? Name these muscles.

Back 22

The shoulder internal rotators (pectoralis major, latissimus dorsi, teres major, and subscapularis) are stronger than the external rotators (teres minor and infraspinatus), which is why posterior shoulder dislocations are more common than anterior dislocations after electrical shock and seizures.

Front 23

Injury to what location of the brachial plexus would not produce Horner's syndrome, a winged scapula, diaphragmatic paralysis, or rhomboid paralysis

Back 23

Postganglionic injuries

Front 24

Injury to cranial nerve XI would cause what deformity of the shoulder? Why would cranial nerve XI injury result in shoulder depression with scapular translation laterally and cause the inferior angle to be rotated laterally?

Back 24

Lateral winging

Unopposed pull of the serratus anterior

Front 25

Injury to the long thoracic nerve (C5-C7) would cause what shoulder deformity?

Back 25

Medial scapular winging. Results in superior elevation with scapular translation medially and the inferior angle rotated medially

Front 26

When does the subclavian artery become the axillary artery?

Back 26

After the subclavian emerges between the anterior and middle scalenes, it becomes the axillary artery at the outer border of the first rib

Front 27

The axillary artery is conceptualized as divided into three parts on the basis of its physical relationship to what?

Back 27

The pectoralis minor muscle (the first part is medial to it, the second is under it, and the third is lateral to it).

Front 28

What are the branches of the axillary artery?

Back 28

Each part of the artery has as many branches as the number of that portion, i.e., 1st part has 1, 2nd part has 2, 3rd part has 3.

Part 1: Supreme Thoracic
Part 2: Thoracoacromial trunk, lateral thoracic
Part 3: Subscapular, anterior humeral circumflex, posterior humeral circumflex

Front 29

What part of the axillary artery is the most vulnerable to traumatic vascular injury?

Back 29

The third part at the origin of the anterior and posterior humeral circumflex arteries

Front 30

What is the interval for the anterior (Henry's) approach to the shoulder?

Back 30

Deltoid (axillary nerve) and pec major (medial and lateral pectoral nerves)

Notes: Anterior (Henry's) surgical approach to the shoulder. In this approach, the interval between the deltoid (axillary nerve) and the pectoralis major (medial and lateral pectoral nerves) is explored. To prevent injury to the musculocutaneous nerve, avoid excessive medial retraction (see medial retractor) on the coracobrachialis or avoid dissection medial to this muscle. Also avoid the axillary nerve, which is inferior to the shoulder capsule. Positioning the arm in adduction and external rotation helps displace the axillary nerve from the surgical field.

Front 31

What 2 nerves are at risk with the delto-pectoral approach to the shoulder?

Back 31

Musculocutaneous nerve and Axillary nerve

Front 32

Where is the Musculocutaneous nerve at risk in the anterior approach to the shoulder? How do you protect it?

Back 32

This nerve usually penetrates the biceps/coracobrachialis 5 to 8 cm below the coracoid, but it enters these muscles proximal to this 5-cm “safe zone” in almost 30% of shoulders. Protect by avoiding vigorous retraction of the conjoined tendon and avoiding dissection medial to the coracobrachialis

Front 33

Where is the axillary nerve at risk in the anterior approach to the shoulder? How do you protect it?

Back 33

Just inferior to the shoulder capsule. Protected during procedures in this area with adduction and external rotation of the arm

Front 34

What is the interval for the lateral approach to the shoulder? What is this approach used for?

Back 34

There is no interval, this is a deltoid-splitting approach in which the deltoid is either split or subperiosteally dissected from the acromion.

This approach exposes the supraspinatus tendon so is used for cuff repair

Front 35

How far inferiorly can the deltoid be split with the lateral approach to the shoulder?

Back 35

No more than 5cm below the acromion in order to avoid injury to the axillary nerve as it exits from the quadrangular space. If dissection is carried below here deneravation of the anterior portion of the deltoid could occur

Front 36

What is the interval for the posterior approach to the shoulder?

Back 36

Infraspinatus (suprascapular nerve) and teres minor (axillary nerve). To access this interval the posterior deltoid must be split.

Front 37

What structures are at risk with the posterior approach to the shoulder?

Back 37

The axillary nerve and the posterior circumflex humeral artery run in the quadrangular space below the teres minor, so you must be sure to stay superior to this muscle

Front 38

What defines the rotator interval?

Back 38

The rotator interval is between the anterior border of the supraspinatus and the superior border of the subscapularis

Front 39

What structure is found within the rotator interval?

Back 39

The superior glenohumeral ligament

Front 40

What is the role of the superior glenohumeral ligament?

Back 40

It is the primary restraint both in inferior translation of the adducted shoulder and in external rotation of the adducted or slightly abducted arm

Front 41

What is the role of the middle glenohumeral ligament?

Back 41

The middle glenohumeral ligament, absent in up to 30% of shoulders, is the primary stabilizer in anterior translation, with the arm slightly abducted (45 degrees)

Front 42

What is the role of the inferior glenohumeral ligament?

Back 42

The inferior glenohumeral ligament complex is the primary stabilizer for anterior and inferior instability in abduction. The inferior glenohumeral ligament complex is composed of the anterior and posterior bands of the inferior glenohumeral ligament

Front 43

What is the attachment of the coracohumeral ligament?
What is the role of the coracohumeral ligament?

Back 43

Attachment: arises from the lateral border of the coracoid process, and passes obliquely downward and laterally to the front of the greater tubercle of the
humerus, blending with the tendon of the supraspinatus muscle

With SGHL, resists inferior translation in adduction; part of pulley to stabilize biceps tendon in joint and groove

Front 44

Name the origin, insertion, action, and innervation for the following muscle:
Trapezius

Back 44

Origin: Medial third of superior nuchal line; external occipital protruberance, nuchal ligament, and spinous processes of C7 - T12 vertebrae

Insertion: Lateral third of clavicle, acromion, and spine of scapula

Action: Elevates, retracts and rotates scapula;

Innervation: Cranial nerve XI

Front 45

Name the origin, insertion, action, and innervation for the following muscle:
Latissimus Dorsi

Back 45

Origin: T6-S5, ilium

Insertion: Humerus, floor of intertubercular groove

Action: Extend, adduct, internally rotate humerus

Innervation: Thoracodorsal nerve (C6-C8)

Front 46

Name the origin, insertion, action, and innervation for the following muscle:
Rhomboid Major

Back 46

Origin: T2-T5 spinous processes

Insertion: Scapula (medial border)

Action: Adducts scapula

Innervation: Dorsal scapular nerve (C4-C5)

Front 47

Name the origin, insertion, action, and innervation for the following muscle:
Rhomboid Minor

Back 47

Origin: C7-T1

Insertion: Scapula (medial spine)

Action: Adducts scapula

Innervation: Dorsal scapular nerve (C4-C5)

Front 48

Name the origin, insertion, action, and innervation for the following muscle:
Levator Scapulae

Back 48

Origin: Transverse process C1-C4

Insertion: Scapula (superior medial)

Action: Elevates and rotates scapula

Innervation: Dorsal Scapular Nerve

Front 49

Name the origin, insertion, action, and innervation for the following muscle:
Pectoralis major

Back 49

Origin: Clavicular head: anterior surface of medial half of clavicle; Sternocostal head: anterior surface of sternum, superior six costal cartilages, and aponeurosis of external oblique muscle

Insertion: Humerus lateral intertubercular groove

Action: Adducts, internally rotates humerus

Innervation: Medial and lateral pectoral nerves

Front 50

Name the origin, insertion, action, and innervation for the following muscle:
Pectoralis minor

Back 50

Origin: Ribs 3-5

Insertion: Coracoid process medial border

Action: Protracts scapula

Innervation: Medial pectoral nerve (C8-T1)

Front 51

Name the origin, insertion, action, and innervation for the following muscle:
Subclavius

Back 51

Origin: Rib 1

Insertion: Inferior clavicle

Action: Depressing clavicle

Innervation: Upper trunk nerves (nerve to the subclavius)

Front 52

Name the origin, insertion, action, and innervation for the following muscle:
Serratus Anterior

Back 52

Origin: Ribs 1-9

Insertion: Ventral medial scapula

Action: Draws scapula forward and upward; abducts scapula and rotates it;

Innervation: Long thoracic nerve (C5-C7)

Front 53

Name the origin, insertion, action, and innervation for the following muscle:
Deltoid

Back 53

Origin: Three parts: Lateral third of clavicle, acromion, and spine of scapula

Insertion: Humerus (deltoid tuberosity)

Action: Anterior part: flexes and medially rotates arm; Middle part: abducts arm; Posterior part: extends and laterally rotates arm

Innervation: Axillary nerve (C5-C6)

Front 54

Name the origin, insertion, action, and innervation for the following muscle:
Teres Major

Back 54

Origin: Dorsal surface of inferior angle of scapula

Insertion: Humerus medial intertubercular groove

Action: Adducts, internally rotates, and extends arm

Innervation: Lower subscapular nerve (C6-C7)

Front 55

Name the origin, insertion, action, and innervation for the following muscle:
Subscapularis

Back 55

Origin: Subscapular fossa

Insertion: Humerus lesser tuberosity

Action: Internally rotates arm, anterior stability

Innervation: Upper and lower subscapular nerves (C5-C7). The upper and middle portions by the upper subscapular nerve, the lower portion by the lower subscapular nerve

Front 56

Name the origin, insertion, action, and innervation for the following muscle:
Supraspinatus

Back 56

Origin: Supraspinous fossa

Insertion: Humerus greater tubercle

Action: Abducts and externally rotates humerus

Innervation: Suprascapular nerve (C4-C6)

Front 57

Name the origin, insertion, action, and innervation for the following muscle:
Infraspinatus

Back 57

Origin: Infraspinous fossa of scapula

Insertion: Middle facet on greater tuberosity of humerus

Action: Laterally rotate arm; helps to hold humeral head in glenoid cavity of scapula

Innervation: Suprascapular nerve (C5-C6)

Front 58

Name the origin, insertion, action, and innervation for the following muscle:
Teres minor

Back 58

Origin: Dorsolateral scapula

Insertion: Inferior facet on greater tuberosity of humerus

Action: Provides stability, externally rotates arm

Innervation: Axillary nerve (C5-C6)

Front 59

What is injured in Erb-Duchenne palsy?
What is the deficit?

Back 59

Upper roots: C5-C6
Weakness of deltoid, rotator cuff, elbow flexors, and wrist and hand extensors “Waiter's tip"

Front 60

What is injured in Klumpke's palsy?
What is the deficit?

Back 60

Lower roots: C8-T1
Weakness of wrist flexors and intrinsic apparatus, Horner's syndrome

Front 61

What has a better prognosis, Erb-Duchenne or Klumpke's?

Back 61

Erb-Duchenne

Front 62

What is the course of the supreme thoracic artery?

Back 62

Comes off first part of the axillary artery and runs medial to serratus anterior and pectoral muscles

Front 63

What are the branches of the thoracoacromial trunk?

Back 63

Deltoid, acromial, pectoralis, clavicular

Front 64

What is the course of the lateral thoracic artery?

Back 64

Comes off second part of axillary artery and descends to serratus anterior

Front 65

What are the 2 branches of the subscapular artery?

Back 65

Thoracodorsal and circumflex scapular (triangular space)

Front 66

What is the major blood supply to the humeral head?

Back 66

Anterior humeral circumflex provides the arcuate artery Comes off third part of the axillary artery and provides blood supply to the humeral head via the arcuate artery lateral to bicipital groove

Front 67

What is the course of the posterior humeral circumflex artery

Back 67

Comes off third part of the axillary artery and runs in the quadrangular space with the axillary nerve

Front 68

What structures define the triangular space and what is found within it?

Back 68

Triangular space: bordered by teres minor (superiorly), teres major (inferiorly), and long head of biceps brachii (laterally)
Contains the circumflex scapular vessels

Front 69

What structures define the quadrangular space and what is found within it?

Back 69

Quadrangular space: bordered by the teres minor (superiorly) and teres major (inferiorly); medial border formed by the long head of the triceps, and lateral border formed by the humerus

Transmits the posterior humeral circumflex vessels and the axillary nerve

Front 70

What structures define the triangular interval and what is found within it?

Back 70

Triangular interval: immediately inferior to the quadrangular space and bordered by the teres major (superiorly), long head of the triceps (medially), and lateral head of the triceps or the humerus (laterally)

Through this interval, the profunda brachii artery and radial nerve can be seen

Front 71

What fascia extends between the coracoid prcoess, the clavicle, and the thoracic wall?

Back 71

Clavipectoral fascia

Front 72

What are the boundaries of the axilla?
Medial wall:
Lateral wall:
Posterior wall:
Anterior wall:
Base:
Apex:

Back 72

Medial wall: Upper ribs and their intercostal muscles and serratus anterior muscle
Lateral wall: Humerus
Posterior wall: Subscapularis, teres major, lats
Anterior wall: Pec major and minor
Base: Axillary fascia
Apex: interval between clavicle, scapular, & 1st rib

Front 73

What 3 groups of arteries form the arterial anastomoses around the scapula?

Back 73

1. suprascapular, descending scapular, and circumflex scapular

2. Acromial and posterior humeral circumflex

3. Descending scapular and posterior intercostal

Front 74

The clavicle is the most commonly fractured bone in the body, where is the weakest point?

Back 74

At the junction of the 2 curves (middle 1/3, it is the narrowest part with no muscle attachments). Clavicle has a double curvature with sternal ventral and acromial dorsal curves

Front 75

The sternal end of the clavicle has a small facet as well as a depression laterally to this, what are these for?

Back 75

The facet is inferior and it is for articulation with the first rib. The depression is for attachment of the costoclavicular ligament

Front 76

The roughened acromial end of the clavicle is for attachment of what?

Back 76

Superior surface roughened for deltoid anteriorly and trapezius posteriorly

Front 77

What ligaments attach to the inferior surface of the clavicle? What is their orientation?

Back 77

Conoid ligament attaches at the conoid tubercle. There is an oblique line extending from here called the trapezoid ridge where the trapezoid ligament attaches.

Conoid is medial, trapezoid is lateral. These ligaments attach the clavicle to the coracoid (CC ligaments)

Front 78

What is the purpose of the clavicle?

Back 78

Serves as a fulcrum for lateral movement of the arm & serves as an attachment for the upper extremity

Front 79

What does a Zanca view evaluate and how is it done?

Back 79

Evaluates AC joint. AP of ACJ with 10 degrees cephalic tilt

Front 80

What view is used to evaluate the SC joint? How is it performed?

Back 80

Serendipity. 40 degree cephalic tilt to the manubrium

Front 81

What XR views can be used to evaluate for a hill-sachs? What view for bony bankart?

Back 81

Hill Sachs: Stryker notch. Hand on head, 10 deg cephalic tilt

Bony Bankart: West Point. Prone, beam into axilla. Assesses the anterior inferior glenoid

Front 82

If an axillary lateral cannot be performed secondary to pain, what view can take its place?

Back 82

Velpeau. Done by having patient lean backward at 45 degrees (leaning back with table at low back) with beam pointed direction superior to inferior at the shoulder joint

Front 83

Clavicle fractures are divided into group 1-3 with group 1 being middle 1/3, 2 being distal 1/3, and 3 being proximal 1/3. Type 2 is broken down further, describe these

Back 83

I: Lateral to CC ligaments
2a: Medial to CC ligaments
2b: Between CC ligaments (conoid torn, trapezoid intact)
3: Fx into AC joint

Front 84

What are the grades of AC joints separation?

Back 84

Rockwood grades:
I: AC ligament sprain
II: AC tear, CC intact
III: AC & CC ligament tears <= 100% superior displacement
IV: Grade III w/ posterior displacement
V: Grade III <= 300% superior displacement
VI: Grade III w/ inferior displacement

Front 85

What is the treatment for the different grades of AC injury?

Back 85

Grades I&II: sling, rest, PT

Grade III: controversial. Nonop for most, CC reconstruction for high level athletes & laborers

Grades IV-VI: CC ligament reconstruction

Front 86

What makes up the parts associated with the neer classification for proximal humerus fractures?

Back 86

Anatomical neck, surgical neck, greater tuberosity, lesser tuberosity.

To be called a part, must be displaced > 1cm (0.5 for greater tuberosity) or angled > 45 deg

Front 87

What are the attachments and role of the following ligament?

Superior glenohumeral ligament

Back 87

Attachments: Anterosuperior glenoid rim/labrum to proximal lesser tuberosity

Resists inferior translation and ER in shoulder adduction. Resists posterior translation in 90 degrees of forward flexion

Front 88

What are the attachments and role of the following ligament?

Middle glenohumeral ligament

Back 88

Anterosuperior glenoid rib/labrum (inferior to SGHL) to just medial to lesser tuberosity

Resists anteroposterior translation in 45 deg of abduction. Secondary restraint to translation & ER in adduction

Front 89

What are the attachments and role of the following ligament?

Inferior glenohumeral ligament

Back 89

MOST IMPORTANT LIGAMENT, FORMS SLING THAT TIGHTENS IN ABDUCTION & ER (ANTERIOR BAND) / IR (POSTERIOR BAND)

Attachments:
- Anterior Band: Anterior glenoid/labrum (3 o'clock) to inferior humeral neck
- Posterior band: Posterior glenoid/labrum (9 o'clock) to inferior humeral neck. Resists posterior translation in IR & 90 deg flexion

Front 90

What is a Buford complex?

Back 90

Thickened MGHL & absent anterior/superior labrum

Front 91

From where does the 3 sisters vasculature arise and where is it found?

Back 91

3 sisters run transversely across the inferior border of the subscapularis. These are branches from the anterior humeral circumflex. The axillary nerve runs just inferior

Front 92

Where does the musculocutaneous nerve penetrate the biceps/coracobrachialis?

Back 92

5-8 cm below the coracoid

Front 93

Where is the axillary nerve located in relation to the posterior corner of the acromion? From the midportion?

Back 93

5.5 cm from posterior corner
8 cm from the mid-portion

Front 94

Where is the dorsal scapular nerve found in the shoulder?

Back 94

Deep to the rhomboid major and minor 1-2 cm medial to the border of the scapula

Front 95

Where can a superior portal be placed in order to protect the suprascapular nerve?

Back 95

Placement at the junction of the medial two thirds and lateral third of the superior scapular border provides >= 10mm distance

Front 96

What is the course of the axillary nerve?

Back 96

The nerve travels anterior to the subscapularis 3-5 mm medial to the musculotendinous border,
wraps around the surgical neck of
the humerus, and passes through the
quadrangular space to innervate the
teres minor and deltoid muscles. The nerve lies between 4.3
and 7.4 cm from the lateral edge of
the acromion.1
After entering the
posterior third of the deltoid, the
nerve travels along the deep deltoid
fascia to innervate the middle and
anterior thirds of the deltoid sequentially. The nerve to each head of the
deltoid does not branch until it
crosses each raphe.

Front 97

What is the course of the suprascapular nerve?

Back 97

The suprascapular nerve originates from the fifth and sixth anterior cervical roots. The suprascapular
nerve takes form at Erb’s point from the upper
trunk of the brachial plexus. The nerve then travels laterally, across the posterior cervical triangle, deep to the posterior belly of the omohyoid muscle. It then traverses posteriorly into the supraspinatus fossa through the suprascapular notch under the transverse scapular ligament giving off motor fibers to the supraspinatus. It then travels obliquely along the floor of the supraspinatus fossa toward the rim of the glenoid. The nerve then travels around the spinoglenoid notch into the infraspinatus fossa under the spinoglenoid ligament (inferior transverse scapular ligament)

Front 98

What are the 3 broad categories that the muscles of the scapular region can be classified into? Which muscles are in each category?

Back 98

Superficial extrinsic: Join axial skeleton to the appendicular skeleton (Trapezius, latissimus dorsi). Together, these muscles originate from the entire length of the thoracic vertebral column (C7-T12) and insert laterally onto the clavicle, scapular, and humerus

Deep extrinsic muscles elevate and retract the scapula. There are 3 of these (levator scapulae, rhomboid minor, rhomboid major)

Deep 'intrinsic' or true scapular: Include the rotator cuff, the deltoid, and teres major.

Front 99

Describe the anastomotic network of arteries around the scapula with the axillary artery ligated distal to the thyrocervical trunk

Back 99

If the axillary artery were ligated distal to the thyrocervical trunk, blood would flow from the subclavian through the thyrocervical trunk into the transverse cervical and suprascapular arteries. The transverse cervical anastomoses with the Dorsal scapular artery to supply the medial aspect of the scapula and the inferior angle. The Suprascapular artery anastamosis with the circumflex scapular artery which is a branch from the subscapular artery. The subscapular artery would supply back flow to the axillary artery to continue with the blood supply to the remaining upper extremity.