Download Scapula and Shoulder

Shoulder Anatomy Guide—Things to find in the lab
Muscles
Deltoid: from clavicle, acromion, scapula spine to humerus, axillary nerve, needed for
reverse TSA
Rotator cuff:
Suprapinatus: from supraspinatus fossa to greater tuberosity, suprascapular nerve,
most commonly torn cuff tendon
Infraspinatus: from infraspinatus foss to greater tuberosity, suprascapular nerve,
out with spinoglenoid cyst from labral tear
Teres Minor: from lateral border of scapula to greater tuberosity, axillary nerve
Subscapularis: from anterior scapula to lesser tuberosity, upper and lower
subscapular nerves, tendon fibers extend laterally to create transverse
humeral ligament over biceps groove
-tears lead to long head of biceps subluxations
-confluent with capsule laterally, divergent medially, reflected
with anterior approach
Teres major: inferior lateral scapula to intertubercular groove, lower subscap
nerve, internal rotation and adduction.
Latissimus Dorsi: T7-T12 and iliac crest to intertubercular groove,
thoracodorsal, adduction and IR
Pectoralis major: from clavicle and sternum to intertubercular groove, lateral
and medial
pectoral, adduction and IR
Know the relationship between the Teres Minor, Latissimus and
Pectoralis major muscle insertions for OITE
Pectoralis minor: Ribs to coracoid, medial pectoral, scapulastabilizer, anterior
to axillary aa.
Serratus anterior: ribs to antero-medial scapula, long thoracic nerve, medial
winging when out
Biceps: short (coracoid) and long (superior glenoid) heads, long head is
intraarticular and can be
important pain generator; often involved in SLAP
tears, whack in old people, tenodesis in
younger
The Straps (short head of biceps and coracobrachialis): coracoid to arm, help to
protect neurovascular structures, musculocutaneous nerve
Triceps: 3 origins—long head (infraglenoid tubercle), lateral head (posterior
humerus), medial head (distal posterior
humerus); radial nerve, elbow
extension
Ligaments
Coracoclavicular (CC) ligaments: conoid and trapezoid--conoid is medial and stronger,
run from base of coracoid to undersurface of clavicle
-Provide vertical stability—ruptured with Type III AC injuries
Coracoacromial (CA) ligament: from tip of coracoid to anterior undersurface of acromion
-ligament that connects a bone to itself
-may cause impingement (if you believe in it)
-released with subacromial decompressions
-want to keep if massive cuff tear and concerned about future anterior
glenohumeral escape
Coracohumeral (CH) ligament: extraarticular; found in the rotator interval, resists inferior
translation
Acromioclavicular (AC) ligments: superior is strongest, helps with A-P stability
-don’t over-resect the distal clavicle
or you will detach the superior
ligament attachment (>8mm)
Superior glenohumeral ligament (SGHL):
runs from superior glenoid to lesser
tuberosity, resists posterior/inferior
translation in adduction
Middle glenohumeral ligament (MGHL):
from anterior labrum to anatomic
neck, limits ER and inferior
translation when adducted, limits
anterior translation in 45 degrees abduction
Inferior glenohumeral ligament (IGHL): anterior and posterior component border the
axillary pouch, stabilize in abduction
-anterior component important for anterior stability—fails in anterior dislocations
and leads to Bankart lesion
Rotator interval: capsular tissue between subscap and supraspinatus, boundries are
coracoid, transverse humeral ligament, subcap and supra; contains coracohumeral
ligament and SGHL
Vascular structures
Anterior circumflex: humeral head
Posterior circumflex: greater tuberosity
Thoracoacromial trunk: clavicular, acromial, deltoid, and pectoral branches
Lateral thoracic: to serratus anterior with long thoracic nerve (lateral has ‘a’ for artery)
Spaces
Triangular space: teres minor, teres major, long head of
triceps; contains circumflex scapular artery
Quadrangular space: Teres minor, teres major, long head
of triceps, lateral
triceps; contains axillary nerve,
posterior circumflex artery
Triangular interval: teres major, long and lateral triceps;
contains radial nerve and deep artery of arm
Pathology
Winged scapula:
Accessory nerve CN XI: trapezius and SCM, lateral winging
Long thoracic nerve (C5-7): innervate serratus anterior, medial winging when out
Instability:
TUBS: traumatic, unilateral, Bankart lesion, surgical treatment
Hill Sachs lesion: post. humeral head bony defect from ant dislocation
AMBRI: atraumatic, multi-directional, bilateral, treat with rehab or inferior
capsule repair
Bankart lesion: anterior/inferior labrum tear resulting from ant dislocation, can be bony,
periosteum is torn
ALPSA: anterior labrum periosteal sleeve avulsion; similar to bankart but periosteum
stays intact and labrum medializes
HAGL: humeral avulsion of the anterior IGHL, see contrast leaking at humeral neck
GLAD: glenoid labral articular disruption; anteroinferior labrum tear involving
articular surface, not with dislocations
GIRD: glenoid internal rotation deficit; seen in throwing athletes
SLAP: superior labrum anterior-posterior lesions: labral tears at biceps anchor, common
in throwing athletes
Buford complex: NOT pathologic, anatomic variant where there is an anterosuperior
labrum deficiency associated with a cord-like MGL—DO NOT FIX
Deltopectoal Approach
Internervous plane is axillary (deltoid) and med/lat pectoral (pec major)
Incision: begin by marking out landmarks (coracoid, clavicle, acoromion)
Straight incision from lateral coracoid to deltoid insertion in plane between
deltoid and pec major, cephalic vein runs in this interval
Superficial dissection:
Continue dissection through subq tissue maintaining hemostasis. Bring the
cephalic vein either medial or lateral according to your preference. There tend to be more
branches on the lateral side but bringing it medially helps to protect it during glenoid
preparation. The clavipectoral fascia is opened on the lateral side of the coracobrachialis.
The interval is developed and the “3 sisters” (anterior circumflex a. and accompanying 2
veins) are tied off.
Deep dissection
The subscap is identified attaching to the lesser tuberosity. It can be released just
medial to its insertion to leave some tendon for reattachment during closure. The interval
between the subscap and capsule is developed and the 2 layers are taken down
individually. The subscap and capsule are divergent medially and are more easily
separated here. The long head of the biceps can be found in the intertubercular groove
just lateral to the subscap attachment. Tendon fibers continue over the groove as the
transverse humeral ligament.
Brachial Plexus (C5-T1)
Real Tarheels Drink Cold Beer
(Roots, Trunks, Divisions, Cords, Branches)
Roots: C5-T1, long thoracic and dorsal scap
Trunks: upper, middle, lower; suprascap n.
Divisions: anterior/posterior for each trunk
Cords:
Lateral :C5,6,7 contributions, lat
pect n., musculocutaneous, median
Medial: C8, T1 contributions, med
pect n, media brachial and antebrachial
cutaneous nn, median, ulnar
Posterior: C5-T1 contributions,
upper and lower subscaps, thoracodorsal,
axillary, radial
Long thoracic nerve (C 5, 6, 7): serratus
ant.
Dorsal scapular nerve (C 3,4,5): levator
scap, rhomboids
Suprascapular nerve (C5-6): supra- and infra- spinatus; under ligament, can be
compressed at spinoglenoid notch
Lateral pectoral nerve (C5,6,7): pec major and minor, named for cord origin
Medial pectoral nerve (C8-T1): pic major and minor, named for cord origin
Upper and lower subscaps (C5-6): subscapularis, lower also gets teres major
Thoracodorsal nerve (C7-8): between upper and lower subscaps, latissimus dorsi, runs with artery
Medial cutaneous nerve of arm (C8-T1): sensory only
Medial cutaneous nerve of forearm (C8-T1): medial forearm sensation, runs with basilic v.
Ulnar nerve (C8-T1): FCU, ulnar half of FDP, palmaris brevis, FPB (deep head), ADM, FDM,
opponens, dorsal and volar interossei, ulnar two lumbricals; sensation to half of ring and small
fingers; runs in cubital tunnel post to med epicondyle then between 2 heads of FCU on to
Guyons canal;
Median nerve (C6,7,8,1): pronator teres, FCR, PL, FDS; AIN: radial 2 FDP, FPL, PQ; recurrent
motor branch: APB, opponens pollicis, FPB (superficial head), radial 2 lumbricals; runs
between 2 heads of PT through ligament of Struthers and under FDS to carpal tunnel; sensation
to palm and radial 3 ½ fingers
Axillary nerve (C5-6): deltoid and teres minor, runs with post circumflex humeral artery through
quadrangular space, identified during open shoulder surgery with “tug test”: pulling on nerve
in axillary pouch and feeling it tension on the underside of the deltoid
Radial nerve (C5-T1): triceps, anconeus, ECRL, ECRM, BR, PIN: ECU, EDM, EDC, supinator,
APL, EPB, EPL, EIP; runs with deep artery of arm in triangular interval into spiral groove and
divides into PIN and sensory branch at elbow, PIN runs between 2 heads of supinator;
sensation to posterior forearm and dorsal 3 ½ radial fingers
Musculocutaneous nerve (C5-7): coracobrachialis, biceps, brachialis; pierces through
coracobrachialis, can be injured with excessive medial retraction of strap muscles, continues on
as lateral cutaneous nerve of forearm