Dr. Atif Shahzad PGR

Orthopedic Dept. SHL

DEFINITION:Instability:• Inability to maintain the humeral head in the glenoid

fossa.

• Includes a spectrum of disorders

Dislocation

Complete loss of glenohumeral articulation

Subluxation

Partial loss of glenohumeral articulation with symptoms

Laxity

Incomplete loss of glenohumeral articulation

unassociated with pain

STABILITYStatic Factors

Articular Congruence

Articular Version

Glenoid Labrum

Capsule and Ligament

Dynamic Factors

Rotator Cuff

Biceps Tendon

Scapulothorasic Motion

Negative Pressure

Propioception

OSTEOLOGY Glenoid fossa

Pear shaped

7 deg. of retroversion

5 deg. of sup tilt

Glenoid version

30o anterior

Humerus

Neck-shaft – 130o to 140o

Retrotorsion – 30o

GLENOHUMERAL JOINT Humeral head 3x larger

than glenoid fossa

Ball and socket with translation

3 degrees of freedom

Flex/Ext

Abd/Add

Int/Ext rot

Plus

Cricumduction

GLENOID LABRUM Static stabilizer

contributes 20% to GH stability

Fibro cartilaginous tissue

Deepens glenoid(50%)

3purposes:

Inc. surface contact area

Buttress

Attachment site for GH ligaments

CAPSULE AND LIGAMENTSCapsule

Attached medially glenoid fossa

laterally to anatomical neck of humerus

Ant cap thicker than post.

2-3 mm of distraction

Little contribution to joint stability

Strengthened by GHLs and RC tendons

GLENOHUMERAL LIGAMENTS(Superior, Middle , Inferior)

SGHL

O = tubercle on glenoid just post to long head biceps

I = upper end of lesser tubercle

Resists inf. subluxation and contributes to stability in post and inf. directions

MGHL

O= sup glenoid and labrum

I = blends with subscapularis tendon

Limits ant. instability especially in 45 deg abduction position

Limits ext rotation

IGHL

O= ant. glenoid rim and labrum

I= inf. aspect of humeral articular surface and anatomic neck

3 bands, anterior, axillary and posterior

Acts like a sling ,the most important single ligamentous stabilizer .

Primary restraint is at 45-90 deg abduction.

Coracoacromial ligament

secondary stabilizer.

Coracohumeral ligament

Contribute to restraining inferior subluxation with arm at side,

Dynamic Factors

Rotator Cuff

Biceps Tendon

Negative Pressure

Scapulothoracic motion

Proprioception

ROTATOR CUFF Compression enhances conformity

Greater than static stabilizers

Coordinated contractions/steering effect

Supraspinatus most important

Dynamization

Biceps long head, Deltoid

secondary stabilizer head depressor

Periscapular Muscles

help position scapula and orient glenohumeral jointcontributes compressive force across joint

SCAPULOTHORACIC MOTION 2:1 glenohumeral to scapulothoracic motion

Scapulothoracic muscle (trapezius, serratus anterior, teres major, levator scapulae)

less stable platform

NEGATIVE INTRA-ARTICULAR PRESSURE -42 cm H2O in cadaver

Secondary to high osmotic pressure in interstitial tissues

Only clinically important in the arm at rest in adduction

Lost with lax capsule or defect

PATHOANATOMY OF SHOULDERINSTABILITY

Laberal Lesions – Bankart – Reverse Bankart – SLAP lesions

Capsular Injury – Intrasubstance Tear – HAGL – Capsular Laxity

Bone Loss – Glenoid – Humeral Head-Hill-Sachs Lesion

BANKART LESION.

The traumatic detachment of the glenoid labrum has been called the Bankart lesion. 85%

HILL-SACHS LESION

This is a defect in the posterolateral aspect of the humeral head.

INSTABILITYClassification:

Frequency

Etiology

Direction

Degree

Frequency Acute

Recurrent

Fixed (chronic)

Etiology Traumatic event (macrotrauma)

Atraumatic event (voluntary, involuntary)

Microtrauma

Congenital condition

Neuromuscular condition (epilepsy, seizures)

Directions of instability

Anterior

Posterior

Inferior

Superior

Multidirectional

Degree

Subluxation

Dislocation

SPECTRUM

Traumatic Microtrauma Atraumatic

Less laxity More laxity

Unidirectional Multidirectional

EVALUATION OF INSTABILITYHistory Age

Trauma-Duration

Associated Pain

Sports, throwing or overhead activities

Voluntary subluxation

“Clunk” or knock

Fear-Limitation of Movements

Hx dislocationsand energy associated

Hx 1st dislocation or injury

Subsequent dislocations/ subluxations

Physical Examination

Inspection

Palpation

ROM

Winging

Neurovascular testing

Generalized ligamentous laxity

Instability tests

Sulcus sign

Drawer tests

Load & Shift test

Apprehension test

Jobe’s Relocation

Jerk test

Fulcrum

Grade = 1 - 4

DIAGNOSIS X-rays

CT Scan

MRI

Arthroscopy

RADIOLOGY X-Rays

Identify Bankart or Hill-Sachs Lesion

AP VIEW

Axillary View

Scapular Y-View

Stryker view Humeral Head Defect

Apical Oblique view Glenoid rim lesion

West Point Axillary view Anteroinferior glenoid rim

ANTERIOR DISLOCATION97% of recurrent dislocation

abduction, extension and

external rotation

subcoracoid

subglenoid

subclavicular

Associated Injuries:

Fractures

Head & Neck

Rotator Cuff Tears > 40 y/o = 30 %

> 60 y/o = 80%

Neurologic Injury

Axillary nerve

10-25% incidence 1st time.

2-5% in recurrent dislocators

Tx: “watchful expectancy”

Poor prognosis if no recovery by 10 wks

Vascular Injury

Axillary artery

2nd part thoracoacromial

trunk

TREATMENTNONOPERATIVE

Closed Reduction

Immobilization-Sling

Analgesics

Rehabilitation

ROM

Strengthening exercises

Treatment of 1st time dislocators :

2 groups

Immobilize x 4wks

80% recurrence

Surgical repair

14% recurrence

TREATMENT OF RECURRENT ANT. DISLOCATION

Non-operative Tx:

Only 16% traumatic respond

80% atraumatic respond

Poor response to non operative Tx

Surgical stabilization

Open or arthroscopic

MATSEN'S CLASSIFICATION TUBS:

Traumatic

Unidirectional

Bankart lesion

Surgery is often necessary.AMBRI:

Atraumatic

Multidirectional

Bilateral

Rehabilitation is the primary mode of treatment.

Inferior capsular shift & internal closure often performed.

OPERATIVE TREATMENT:Capsulolabral Repair

Bankart

Modified Bankart

Subscapularis Procedures

Putti-Platt

Magnuson-Stack

Coracoid Transfer Procedures

Bristow

Latarjet

POSTERIOR DISLOCATION

Incidence: < 5% all shoulder dislocations

3% of recurrent

Mechanism:

Axial load

Flexed/Adduction

Bench press-“lock out”

Swimming- pull thru

Rowing

Football Offensive Lineman

Examination

Shift & load test

Post. Apprehension test

Jerk test

Kim test

Imaging studies

X-ray

CT

MRI

TREATMENTNon Operative

Immobilization

Protection

Rehabilitation

70-90% improve

Functional disability

improved

Instability not eliminated

Operative Management

Overall 50-95 % success

Higher recurrence vs ant. instability procedures

Soft Tissue Procedures

Posterior Capsulorrhaphy

Reverse Putti-Platt

(IS Capsular Tenodesis)

McLaughlin

Bone Procedures

Posterior Glenoid Osteotomy

Posterior Bone Block

REHABILITATION1. Immobilization in first 4 weeks

No ext rotation

Abduction less than 45°

Isometric resistance exercises

2. Graduated in 4 – 8 weeks

↑ ROM

Graduated weight training

3. Return to sport

Non contact = 6 weeks

contact = 12 weeks

THANKS