shoulder instability
TRANSCRIPT
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