PC Shoulder Flashcards
Primary blood supply to humerus
Posterior Humeral cicumflex
Terminal branch of anterior humeral circumflex
Arcuate artery is terminal branch of anterolateral ascending branch of AHCA
Humeral normal neck shaft angle
130 degrees
Retroversion 30 degrees relative to transepicondylar axis
Dynamic stabilizers of the glenohumarl joint
Rotator cuff (concavity comprssion) Scapular stabilizers
Static stabilizers of glenohumeral joint
Labrum (increases depth up to 50%) Articular version Capsule Glenohumeral ligaments Negative intraarticular pressure
Angle of glenoid relative to scapula
5 degrees retroversion
5 degrees upward tilt
Superior glenohumeral ligament
Resists anterior translation of adducted arm
Middle glenohumeral ligament
Resists anterior translation of arm at 45 deg abduction & ER
Anterior band of IGHL
Resistes anterior-inferior translation of arm at 90 deg abduction & ER
Posterior band of IGHL
Resists posterior-inferior translation in IR and ADDuction
Relative proportion of shoulder motion from glenohumeral joint & scapulothoracic joints
2/3 glenohumeral
1/3 scapulothoracic
First 30 degrees is GLENOHUMERAL only
Timing of clavicle ossifiation to close
Age 20-25
Bleeding occurs when taking down coracoarcomial ligament too medially
Acromial branch of thoracoacromial artery
Most common site of symptomatic Os Acromiale
Junction of meso and meta-acromion
3% incidence
60% bilateral
Relative alignment of CC ligaments
Conoid – medial — bigger and stronger
Trapezoid – lateral
Rotator interval
Between subscapularis and SGHL
Laxity of rotator interval causes
Multidirectional instability
Causes inferior translation
Contraction of rotator interval causes
Decreased ROM — think adhesive capsulitis
Describe regions of the axillary artery & how we split it up
Divided into 3 revions by pectoralis minor muscle
Part I - medial to pec minor – superior thoracic artery
Part II – deep to pec minor — lateral thoracic trunk, throacoarcomial trunk
Part III – lateral to pec minor – anterior humeral circumflex artery, posterior humeral circumflex, subscap artery
Blood supply of anterior humeral circumflex artery
Humeral head
Blood supply of posterior humeral circumflex artery
Posterior greater tuberosity & posteroinferior head
Course of axillary nerve
Passes through quadrilateral space with posterior humeral circumflex
Posterior branch terminates as sensory branch to lateral arm and motor to teres minor
Anterior branch innervates undersurface of deltoid
Define the Triangular Space
Borders: teres minor, teres major, long head of triceps
Contains: Scaular circumflex artery
Define the Triangular Interval
Borders: teres major, long head of triceps, humerus
Contains: Radial nerve, profunda brachii artery