EXSS366- Shoulder Anatomy

Clavicular Fracture

- CAUSE: FOOSH or on the tip of the shoulder - S&S: Patient will support the arm, tilt head to side of injury, swelling, tenderness, deformity - MANAGEMENT: Sling, x-ray, immobilization for 6-8 weeks; adults (pin bones together), children (no surgery)

Arthrokinematics

- Happens between bones but inside the joint to allow osteokinematics to occur; capsular

Osteokinematics

- Movement of the bones - Flexion, extension, abduction, adduction, IR, ER, horizontal abd/add, circumduction

Glenohumeral Joint

-"shoulder" -Shallow glenoid, labrum, golf ball on the tee

Posterior SC Sprain/Dislocation

---medical emergency

Scapula

-Acromion process, coracoid process -Attachment site for many muscles

GH Sprain

-Anterior: forced abduction or ER -Often involves rotator cuff -Posterior: forced posterior translation while in flexion -S&S: Pain in MOI position and palpation -Mgmt: RICE, rehab progression (Often hurt rotator cuff too, because rotator cuff merges in with capsule MOI is REALLY IMPORTANT)

Contusion-- Shoulder Pointer

-Contusion to distal end of clavicle -Often mistaken as an AC sprain

Hill-Sachs Lesion

-Cortical depression in the posterolateral humeral head -Results from forceful impaction of the humeral head against the anteroinferior glenoid rim during anterior dislocation / subluxation (from anterior dislocation)

Glenoid Labrum

-Deepens the glenoid fossa -Increase articular contact area -Helps produce negative articular pressure -Most effective mid range

AC sprain

-Direct blow forces acromion process inferior and posterior also FOOSH -S&S are dependant upon the grade -Mgmt: cold, sling, refer, Grade 1: 3-4 days, Grade 2: 10-14 days, Grade 3:2 weeks, Grade 4-6 require surgery, protection is important (Very common in football Difficult to differentiate grade one from contusion)

AC Joint Sprain- Grade III

-Disruption of AC and CC ligaments, distal instability + Piano key test -Disruption of deltoid and trapezius from distal clavicle -Point tender and pain (may be less than Grade II) -Visible deformity -Possible tenting of skin

Dynamic Stabilizers--Rotator Cuff

-Dynamic capsular tension -Rotator cuff tendons blend into joint capsule -Rotator cuff contraction leads to increased tension of capsulo-ligamentous complexS

Sternoclavicular Joint

-Fibrocartialge disk that moves separately from sternum

Acromioclavicular Joint

-Fibrocartilage disk and Capsule

Bankart Lesion

-Glenoid labrum avulsion with GH ligament -Usually located in the anterior-inferior portion -S/S: Pain, crepitus, "catching" -Increased risk of instability -Conservative or surgical treatment (Same signs and symptoms of meniscal tears They do sew them back down into the glenoid...reattch it so its not moving around... meniscus doesn't pull away from tibia like labrum pulls away from the glenoid)

Humeral Shaft Fracture

-Humeral shaft: Fall or blow, radial nerve -Proximal: Fall or blow, can be mistaken as dislocation -Epiphyseal: more common in young athletes -S&S: Pain, inability to move, discoloration, point tenderness, Check distal circulation - MANAGEMENT: Splint, neurovascular evaluation, x-ray, 2-6 months

AC Joint Sprain- Grade I

-Minor sprain to AC ligaments, stable joint -Point tender and pain -No deformity

Middle Glenohumeral Ligament

-Prevents anterior translation -Limits shld. ER between 0-90° of arm ABD

Superior Glenohumeral ligament

-Prevents inferior translation in shoulder ADD

AC Joint Sprain- Grade II

-Severe enough to rupture AC ligaments, distal instability + Piano key test -CC ligaments intact -PT and pain -Visible deformity (AC widening or "step deformity")

AC Joint Sprain- Grade IV

-Similar to Grade III -Posterior clavicle displacement -Visible deformity *Posterior tenting of skin (IV AND V not anymore significant just a way of describing location)

Clavicle

-Supports anterior portion of the shoulder -Weakest where it changes shape

Force Couples

-Synergistic relationship of muscles to create one motion -Upward rotation and downward rotation - Usually scapular winging, upward rotation, and protraction due to... *Weak lower trap+ Upper Trap tight+ Serratus Weak

SLAP Lesion

-Tear of the superior glenoid labrum near attachment of the long head of the biceps tendon -MOI: *dislocation, subluxation, tension of LH of biceps pulls labrum away from glenoid, common with overhead athletes -S/S: "clicking, popping", deep shoulder pain, possibly pt. tender over LH biceps, + O'Brien test -Rx: conservative or surgical -Types: *I: fraying near biceps insertion *II: avulsion of labrum with assoc. tear of LH biceps *III: bucket handle tear of labrum with displacement *IV: bucket handle tear of labrum with tearing of LH biceps (Deep shoulder pain... almost no pain upon palpation...sometimes point tender over biceps tendon Almost always treated surgically (no need to memorize the types of labral tears))

Coracohumeral Ligaments

-Tight during shoulder ER & elevation (0-60°) -Prevents inferior translation in shld. ADD

SC sprain

-Uncommon, FOOSH, torsion on extended arm -Grade 1: little pain and disability -Grade 2: visual deformity, pain, swelling, pt tender, unable to abduct or hz adduct -Grade 3: Complete dislocation, posterior is dangerous -RICE, refer based on deformity *best indicator is pain with Hz add/abd *posterior dislocation is an emergency

AC Joint Sprain- Grade VI

-Very rare -Severe ABD force -Clavicle displaced under coracoid process

AC Joint Sprain- Grade V

-Very severe Grade III -Entire upper extremity drops inferiorly -Clavicle is very prominent and superior

Sternum

-attachment for the clavicle

Humerus

-bicipital groove -greater and lesser tuberosity

Proximal Humeral Fracture

-note how it could appear as a dislocation

Scapulothoracic Articulation

...

Scapular Function

1. Stable part of GH joint *Proper alignment between glenoid & humerus leads to optimal support from static stabilizers 2. Retraction & protraction along thoracic wall 3. Elevation of acromion during overhead activity *Avoid impingement of rotator cuff muscles 4. Stable base for muscle attachment *Proper alignment between glenoid & humerus leads to optimal function of primary dynamic stabilizers -Length-Tension Relationship 5. Link in transmitting force from proximal to distal segments

Inferior Glenohumeral Ligament Complex

3 components: *Anterior band *Axillary pouch (Functions like a "Hammock" ) *Posterior band Anterior band & axillary pouch *provide anterior stability in upper ranges of ABD Posterior band *provides inferior stability during arm ABD In shoulder ABD: *Anterior band becomes taut with shld. ER *Posterior band becomes taut with shld. IR

Muscular Anatomy- Humerus

Biceps Coracobrachialis Ant, Middle, Post Deltoid Infraspinatus Latissimus Dorsi Pectoralis Major Subscapularis Supraspinatus Teres Major & Minor Triceps

Dislocations/Subluxations-- Anterior Inferior

GH= ABD+ER -Often involves capsule, ligaments RC, and labrum *Bankart lesion: anterior defect in the labrum *Hill Sachs lesion: posterior lateral defect on the humeral head *SLAP lesion: injury to the superior labrum that extends from posterior to anterior and effects attachment of biceps tendon -S&S: Pain, flattened deltoid -Mgmt: Splint, reduction post x-ray, immobilize in ADD IR, surgery vs rehab (VERY PAINFUL Do not reduce first timers! W/out surgery soooo likely to come out again.... Almost everyone has surgery eventually)

Dislocations/Subluxations-- Posterior

GH= ADD/IR or fall on IR arm -Tear of posterior labrum -Fracture of lesser tuberosity if subscap avulses -Reverse Hill Sachs: anteromedial defect -S&S: Severe pain and disability, arm is IR, acromion and coracoid are prominent -Mgmt: Splint, Reduction, immobilize in ABD ER (Can clearly see Coracoid!)

Capsulo-ligamentus Complex

Joint capsule -Thin, weak & relatively loose leads to increased mobility, decreased stability -Coracohumeral ligament -Glenohumeral ligaments *Superior, Middle, & Inferior -Role in stability varies with shoulder position & direction of translating force

Muscular Anatomy- Scapula

Latissimus Dorsi Levator Scapulae Rhomboid Major & Minor Serratus Anterior Upper, Middle, Lower Trapezius Pectoralis Major & Minor

Dynamic Stabilizers (picture)

Origin and insertion move together, THUS Winging prevents origin from moving... compromises optimal length tension relationship!

Static Shoulder Stabilizers (Posterior View)

Posterior View

Scapulohumeral Rhythm

Scapulohumeral Rhythm -2:1 ratio -During flexion and abduction, for every 2 degree of glenohumeral movement, scapular upwardly rotates 1 degree -Important in maintaining the length-tension relationship of the rotator cuff muscles (Origin and insertion move together, THUS Winging prevents origin from moving... compromises optimal length tension relationship!)