Shoulder/ Arm Flashcards
Anatomic Location of Brachial Plexus
Trunks: Above clavicle. Ontop of anterior scalene, lateral to interscalene space.
Divisions: Posterior to clavicle
Cords: Oriented in relation to axiallary a. (med, lat, post). Posterior to pec minor.
Boundaries of the Axilla
- Posterior: subscapularis & teres major
- Anterior: pec major & minor, subclavius & clavipec fascia
- Medial: upper seratius anterior.
- Inferior: 4th rib
Draw the Brachial Plexus
Branches:
- Dorsal Scapular- Rhomboids, levator scapulae
- N. to Subclavisu - Subclavius
- Long Thoracic- Serratus Ant.
- Suprascapular N. - Supra & Infra
- Upper Subscapular N. - Subscapularis & Teres Major
- Lower Subscapular N. - Subscapularis & Teres Major
- Thoracodorsal - Latissiumus Dorsi
- Medial Pectoral N. Pec Minor, Pec Major
- Lateral Pectoral N. Pec Major
- Med Antebrachial Cutaneous N of Arm - medial sensory to arm
- Med Antebrachial Cutaneous N. of Forearm - medial sensory to forearm
- Musculocutaneous
- Median
- Ulnar
- Radial
- Axillary
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Describe the Orientation of the Glenoid & Scapula
Glenoid:
- 7 degrees retroverted, to 10 degrees anteverted
- 5 degrees superior angulation
- Reletive to long axis of the scapula (on a sagittal cut, a line bisecting the glenoid through the apex of the scapula)
Scapula:
- 3 degrees superior tilt
- Lays 30 degrees anteverted relative to chest wall (hugs the chest wall as it curves around your flank)
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Neck Shaft Angle of Humerus
130 Degrees compared to transepicondylar axis of humerus
Parsonage Turner Syndrome
Neuritis of the brachial plexus
- Sudden onset pain and paresthesias down the arm
Commonly affects C5, C6, suprascapular n., long throacic n., axillary n.
Self-limiting with prolonged recovery (1-2) years
Scapular Winging (Definitition, Affected Muscles & Associated N.)
Def’n: Deviation of the apex of the scapula reletive to its normal orientation
- Medial: Serratus Ant (Long Thoracic N.)
- Lateral:
- Rhomboids (Dorsal Scapular N.)
- Trapezius (Accessory N. [CNXI])
Preclavicular Branches of Brachial Plexus
- Dorsal Scapular N.
- Long Throacic N.
- N. to Subclavius
- Suprascapular N.
Coracohumeral Ligament (Attachements? Function?)
Attachements: Base of coracoid to superior aspect of anatomic neck of humerus
Function: Resists superior translation and ER (similar to SGHL)
Attachements to the Coracoid (Ligaments & Tendons)
Ligaments:
- Coracoclavicular Ligaments
- Trapezoid (lateral)
- Conoid (medial)
- Coracohumeral Ligament
- Coracoacromial Ligmaent
Tendons:
- Coracobrachialis
- Pec Minor
- Short Head of Biceps
Grading of AC Joint Injuries
- No displacement: AC and CC ligaments intact. Sprain.
- Disruption of AC ligaments, <50% displacement. CC ligaments intact
- 50-100% displacement. AC and CC ligaments disrupted.
- Posterior dislocation of the clavicle into trapezius fascia
- 100-300% displacement of clavicle. AC, CC disrupted. Deltoid and trapezial fascia disrupted.
- Clavicle displaced inferior to coracoid
Muscles Connecting the Upper Limb to the Thoracic Wall
- Serratus Anterior
- Pec Major
- Pec Minor
- Subclavius
Muscles Connecting the Upper Limb to the Vertebral Column
- Trapezius
- Latissimus
- Rhomboid Major & Minor
- Levator Scapulae
- Sternocleidomastoid*
Variations in the Capsolabral Complex
- Sublabral Foramen: detatchment of the anteriosuperior labrum. Does not extend past 3’o’clock
- Sublabral Recess: detatchment of the superior labrum often mistaken for SLAP tear
- Buford Complex: Congenital abscence of anterosuperior labrum with cord-like MGHL. Present in approx 2% of population.
Inferior Glenohumeral Ligament (IGHL)
- Anterior IGHL:
- Resist inferior translation
- Effective in 90 degrees abduction
- Posterior IGHL
- Resists posterioinferior translation
- Effective in IR and Adduction with shoulder flexed