Shoulder & Humerus (brian) Flashcards
What is the version of the glenoid? relative to what?
scapula position relative to chest wall?
Average 5 degrees. Range 7 retro to 10 anteverted
75% retroverted 7 degrees
25% anteverted 2-10 degrees
relative to the long axis of the scapula - on axial slice, a line connecting midpoint of glenoid with medial apex of scapula
tilted 3-5 degrees upwards
scapula positioned 30 degrees anterior relative to chest wall/coronal plane
What is the version of the proximal humerus in relation to the transepicondylar axis?
30 degrees retroverted
What is the neck-shaft angle of the humerus?
version? relative to what?
130-150 degrees (130 degrees average)
30 degrees retroverted relative to transepicondylar axis of elbow
What is the carrying angle in men and women?
Men: 10-15 degrees Women: 15-20 degrees
Describe Bauman’s angle. What is the normal value?
Angle formed by a longitudinal line down the humeral shaft and another along the open capitellar physis. Normal: 72 degrees
suprascapular notch: bound by what ligament?
contains what structure?
What related structure is not within the notch? relationship to the ligament?
Superior transverse scapular ligament. Suprascapular vessels are over the nerves “Army over Navy” “Army over, Navy under”
i.e. the notch contains the suprascapular nerve, with the ligament overlying it and the vessels just above the ligament
What are the muscles and nerves affected in medial/lateral scapular winging?
Medial winging: serratus anterior: long thoracic nerve
Lateral winging: Trapezius: CN 11, or accessory nerve
Rhomboids: dorsal scapular n
Name 3 anatomic variants of the shoulder labrum aside from the normal:
Buford complex: absence of the anterosuperior labrum with a thickened MGHL
Sublabral foramen - anterosuperior labrum appears detached from glenoid - looks like a tear
sublabral recess - superior labrum appears detached from glenoid - looks like a SLAP tear
describe the path of the axillary artery and its branches
once subclavian artery crosses first rib, becomes axillary artery
part I (1 branch): before (medial to) pec minor–gives off supreme thoracic branch
part II (2 branches): deep to pec minor–gives off thoracoacromial artery and lateral thoracic artery
part III (3 branches): lateral to pec minor–gives off subscapular artery, anterior and posterior humeral circumflex arteries
crosses teres major and becomes brachial artery
where does the subclavian artery become the axillary artery?
At the lateral edge (after) the 1st rib
Where does the brachial plexus become superficial?
At the distal end of clavicle
Where do the trunks of the brachial plexus lie?
On the anterior scalene muscles
What are the attachments to the greater tuberosity?
Superior facet: supraspinatus (s=s, super = supra) Middle facet: infraspinatus Inferior facet: teres minor
What is the attachment to the lesser tuberosity?
sometimes some of supraspinatus according to 2009 JBJS paper 2009;91
How much of the trochlea is covered with articular cartilage? (how many degrees of the arc)
300 degree arc
Which direction is the distal humeral articulation of the elbow rotated in the axial plane? In the long (sagittal) plane? Varus/valgus (Coronal plane)?
Axial: 5-7deg IR Sagittal: 30deg anterior rotation 6-8deg valgus tilt
What is the column theory of the distal humerus?
3 column theory: - Medial, lateral, distal columns (like a spool in your fingers) - Medial column diverges from humeral shaft at 45 deg - Lateral column diverges from humeral shaft at 20 deg
What prevents AP displacement of the clavicle?
What ligaments are included in the sternoclavicular joint?
Anterior SC ligament
Posterior SC ligament
What constitutes the conjoint tendon of the shoulder?
Coracobrachialis & Short head of biceps
Suprascapular notch; Compression here affects what?
Suprascapular nerve - Affects both supra and infraspinatus
What is a Buford complex?
Normal anatomical variant: Congenital absence of anterosuperior labrum with cord-like middle GH ligament - 2% of population - Normal variant
O: Mastoid I: sternal manubrium, 1/3 sternal end of clavicle N: Accessory nerve A: Head extension, lateral tilt, contralateral rotation
O: External occipital protuberance, superior nuchal line, SP C7-T12 I: Scapular spine, acromial 1/3 of clavicle N: Accessory nerve A: elevates shoulder girlde, rotate scapula
O: - Major SP T2-5 - Minor SP C7-T1 I: Medial scapula I: Dorsal scapular nerve A: Scapular adduction and rotation
Levator Scapulae: OINA
O: TP C1-4 I: Superomedial scapula I: C3, C4 A; Scapular elevation and rotation
When does the clavicle ossify? when does it fuse?
ossify at 5 wks GA, fuse at 25yrs
clavicle is the first bone to ossify and last to fuse