dr. js kirsten louis leipoldt medical centre room 333, broadway

GLENOHUMERAL GLENOHUMERAL

INSTABILITYINSTABILITY

Dr. JS KirstenDr. JS Kirsten

Louis Leipoldt Medical CentreLouis Leipoldt Medical Centre

Room 333, Broadway, BellvilleRoom 333, Broadway, Bellville

Historical overviewHistorical overview

• Early descriptions

– Hippocrates 460 BC

• Anterior capsule

– Thirteenth century

• Humeral head defect

– 1861

• Rotator cuff injuries

– 1880

• Muscle defects

– 1954

– Subscapularis tendon


• Treatment of acute

traumatic dislocation

– Hippocrates: Six

different techniques

– Kocher - 1817

– Milch - 1938


• Posterior

glenohumeral

instability - 1839

– Diagnosis without x-

rays

– X-rays discovered late

1800’s


• Operative

reconstruction for

anterior instability

– Hippocrates: White hot

poker to scar capsule.

– More refined

techniques - 1868 -

1923 (Bankhart)

Relevant AnatomyRelevant Anatomy

• Skin

– Cosmetically

acceptable incisions in

lines of skin.

• First muscle layer

– Deltoid

– Supplied by axillary

nerve

– Surgical approaches


• Coracoacromial arch

– Coracoid serves as

landmark during

surgery.


• Humeral scapular

motion interface.

– Not moving: Deltoid,

coracoid muscles,

acromion,

coracoacromial

ligament.

– Moving: Rotator cuff,

long head of biceps,

humeral tuberosities.


• Rotator cuff

– Subscapularis

– Rotator interval

– Supraspinatus

– Infraspinatus

– Long head of biceps


• Scapulohumeral

ligaments

– Superior glenohumeral

ligament, middle

glenohumeral

ligament, inferior

glenohumeral

ligament.


• Scapulohumeral ligaments

– Relaxed throughout most of range of motion.

– Play role primary in positions near extremes

of motion.

– Proprioceptive function.


• Glenoid labrum

– Consists of tense

fibrous tissue.

– Anteriorly continuous

with inferior

glenohumeral

ligament.

– Plays role in stability


• The scapular humeral ligaments under tension– Superior glenohumeral ligament:

• External rotation in adduction.

– Middle glenohumeral ligament:• External rotation in abduction to 45 degrees.

– Inferior glenohumeral ligament:• Anterior band in wide abduction and external rotation.

• A posterior band together with rotator interval when humerus elevated anteriorly in sagittal plain (flexion).

Mechanism of glenohumeral Mechanism of glenohumeral

stabilitystability

• Net humeral joint

reaction force


stabilitystability

• Effective glenoid

arch.

Glenoid versionGlenoid version

• Angle that glenoid centre line makes with

plain of scapula.

• Altered by dysplasia, fractures, osteotomy,

arthroplasty.

• Abnormal relationship to forces generated

by scapulohumeral muscles.


stabilitystability

• Glenoid version

• Scapular

positioning

• Ligaments

• Rotator cuff.


stabilitystability

• Net humeral joint

reaction force

directed within

effective glenoid arch.

• Glenoid and humeral

joint surfaces

congruent.

• Head will remain

centered.

Net humeral joint reaction forceNet humeral joint reaction force

• Rotator cuff

• Deltoid

• Long head of

biceps.


• Strengthening and neuromuscular training

optimize control.

• Control impaired by injury, disuse,

contracture, paralysis, loss of coordination,

tendon deffects.

• Control guided by proprioceptors in labrum

and ligaments.


• Generalized joint laxity - less acute

propriocepsion and altered muscle activation.

• Propriocepsion compromised by traumatic

anterior instability.

• Propriocepsion is restored one year after

surgical reconstruction.

• Neuromuscular stabilization, capsular feedback

and pattern generators, muscle optimization.

Scapular positioningScapular positioning

• Scapular alignments increase range of positions in which joint is stable

• Coordination of scapular positioning and glenohumeral muscle balance improved by neuromuscular control

• Most throwing and striking skills shoulder abduction angle usually 100 degrees.

• Higher and lower release points achieved by tilting trunk

LigamentsLigaments

• Strength: Amount of tension before

failure.

• Laxity: Amount of translation or rotation it

allows.

• Laxity does not determine stability.

– Asymptomatic gymnasts or school children.

Ligamentous stabilizationLigamentous stabilization

• Serves as check

reigns.

– Restrict joint position.

– Muscle balance act as

stabilizing force by

compressing head.

– Altered by scapular

position.

– Altered by surgical

capsular tightening.


• Act as countervailing

force.

– Compresses humeral

head into glenoid

fossa.

– Resists displacement.


• Obligate translation.

– When joint is forced to

extremes of motion.

• Late cocking and early

acceleration phase in

throwing.

– Posterior labral tears

and calcification.

– Surgically over

tightening ligaments.

Adhesion/CohesionAdhesion/Cohesion

• Molecular action of fluid to itself and to

joint surfaces.

• Joint fluid: High tensile strength, low

shear strength.

Adhesion/CohesionAdhesion/Cohesion

• Inflammatory disease lowers cohesion.

• Degenerative joint disease lowers wet

ability of surfaces

• Displaced articular fracture or small

glenoid diminishes contact area.

Glenohumeral suction cupGlenohumeral suction cup

• Seal of labrum and capsule to humeral head.

• Flexible peripherally.

• Rigid centrally.

Glenohumeral suction cupGlenohumeral suction cup

• Centers humeral head in glenoid in midrange positions without muscle action.

• Capsule and ligaments not under tension

• Defect in labrum or capsule eliminate suction cup effect

Limited joint volumeLimited joint volume

• Scarcity of fluid in joint.

• Osmotic action of sinovium.

• Lower osmotic pressure in sinovial interstitium.

• Constant negative pressure in joint.

• Attempted distraction lowers inter articular

pressure more.

• Reduced if joint is vented or compliant type

capsule

Stability at restStability at rest

• Adhesion/cohesion.

• Suction cup.

• Limited joint volume.

• Inferior subluxation with

– hemarthrosis

– joint effusion

– surgical incision

– fluid

Superior stabilitySuperior stability

• The same mechanisms as mentioned

before.

• Ceiling effect provided by superior cuff

tendon.

– Interposed between humeral head and

coracoacromial arch.

• Dependant on intact coracoacromial arch.

Types of GH instabilityTypes of GH instability

• Circumstances of instability

– Congenital, chronic locked, recurrent,

traumatic, atraumatic, voluntary.

• Degree of instability

– Dislocation, subluxation


• Direction of instability

– Anterior dislocations

• Fracture of the greater tuberosity, rotator cuff

avulsion, capsulolabral tears

• neurological, vascular and pulmonary

complications can occur

• Direction of instability

– Posterior dislocations.

• Easily missed in 60% to 79% of cases.

• Mechanism is axial loading of adducted and

internally rotated arm.

• Proper physical examination.



• Direction of instability– Inferior dislocations

• Hyper adduction force.

• Humerus locked in 110 to 160 degrees abduction.

• Severe soft tissue injury and fracture of proximal humerus.

– Superior dislocations

• Extreme forward and upward force on an adducted arm.

• Extreme soft tissue damage to cuff biceps tendon and other

muscles.


• Bilateral dislocations

– Convulsions

– Violent trauma.

– Electric shock

Clinical findingsClinical findings

• History

– Injury with arm in extension, abduction and

external rotation favors anterior dislocation.

– Electric shock, seizures or fall on flexed and

adducted arm favors posterior dislocation.


• Physical examination of anterior dislocated

shoulder

– Head palpable anteriorly.

– Hollow beneath acromion.

– Arm held in slight abduction and external

rotation.


• Physical examination of posteriordislocated shoulder– Lack of striking deformity

– Shoulder held in abduction and internal rotation

– Limited external rotation and elevation

– Posterior prominence and rounding of shoulder

– Flattening of anterior aspect of shoulder

– Prominence of coracoid process on dislocated side.

– Long standing cases• Muscle atrophy


• Radio graphic evaluation

– Demonstrate direction of dislocation.

– Associated fractures.

– Barriers to relocation.


• Radio graphic

evaluation

– Note views oriented to

scapula.

• Antero posterior view in

plain of scapula.


• Radio graphic

evaluation


scapula.

• Scapular lateral view.


• Radio graphic

evaluation


scapula.

• Axillary view.

RadiographsRadiographs


• CT scan

– Greater detail

– Anterior inferior glenoid lesions

– Posterior lateral humeral head lesions

Associated injuries Associated injuries –– anterior anterior

dislocationdislocation• Ligaments and

capsule

• Fractures

• Cuff tears

• Vascular injuries

• Nerve injuries


dislocationdislocation

• Ligaments and capsule

– Antero inferior glenohumeral ligaments

from glenoid

• younger individuals.

– Non-healing

• recurrent traumatic instability.

– Capsule sometimes avulse from

anteroinferior portion humerus neck.



• Fractures

– Glenoid

– Humeral head

– Tuberosities

– Humeral neck fracture during attempted

closed reduction.

– Coracoid process



• Cuff tears

– Patients older than forty years

– Ultrasonography, arthrography, MRI

– Prompt repair




– Elderly

• more fragile vessels.

– Axillary artery or vein or its branched avulsed.

– Erect dislocation.

– During reduction and chronic anterior

dislocation in the elderly.

– Mortality 50%.




– Pain, expanding hematoma, pulse deficit,

peripheral cyanosis, peripheral coolness,

pallor, neurological dysfunction, shock.

– Doppler or arteriogram.

– Surgical emergency

– Digital pressure on artery over first rib

– Subclavicular operative approach.



• Nerve injuries

– Mechanism is traction or pressure on

nerve.

– Incidence 33%.

– Different degrees of injury.

– Weakness and/or numbness.

– Most recover completely.

Recurrence of instability after Recurrence of instability after

anterior dislocationanterior dislocation

• Age under 20yrs 33% to 90% chance

• age 20 to 30yrs 25% chance

• age 30 to 40yrs 10% chance.

• Higher chance in athletes and men

Recurrence of instability after Recurrence of instability after


• Effects of post dislocation treatment.

– General consensus on immobilization over

three weeks.

– In physically demanding sport or

occupation

• aggressive post dislocation rehabilitation

program is necessary.

– Return to activities

• no weakness, atrophy or apprehension is

present.

Associated injuriesAssociated injuries--posterior posterior


• Fractures

– Posterior glenoid rim.

– Lesser tuberosity.

– Proximal humeral multi part.

• Other associated injuries

– Rotator cuff and neurovascular injuries.

Treatment of acute traumatic Treatment of acute traumatic


• Timing of reduction and analgesia

– Complete set of radio graphs.

– Rule out associated bony injuries.

– Early reduction.



• Method of reduction

– Without use of medication• Acutely.

– Narcotics and muscle relaxant.• Respiratory depression.

• Resuscitation equipment.

– General anesthesia, brachial plexus block • longstanding locked dislocation.

– Intra articular Lignocaine 20ml.



• Method of reduction

– Traction on abducted + flexed arm with

counter traction on thorax.

– Elbow flexed 90 degrees

• relax neurovascular structures.

– Steady traction on long axis of arm.

– Outward pressure on proximal end of

humerus.

– Post reduction x-rays.

Chronic anterior traumatic Chronic anterior traumatic

dislocationsdislocations

• Reduction and analgesia

– Dislocated for several days.

– Difficulties and complications with reduction.

– Commonly in elderly people or altered mental

status.

– Soft bone.

– Humeral head firmly impaled on glenoid.

– Careful for Kocher maneuver.

Chronic anterior traumatic Chronic anterior traumatic

dislocationsdislocations

• Open reduction

– Altered position neurovascular structures

– Structures tight and scarred.

– Head collapse.

• Humeral head prosthesis.

• Results of treatment of chronic dislocation

– Closed reduction success rate 50%.

Management after reduction of Management after reduction of


• Evaluation

– AP and lateral x-rays

– Neurological status

– Strength of pulse

– Bruits and expanding hematoma

– Rotator cuff integrity



• Protection

– Flexion to 90 degrees.

– External rotation to 0 degrees

– Three weeks.

– Cuff and deltoid isometrics

– Duration of immobilization reduced with

increasing age.



• Strengthening

– Patient is informed.

– Cuff strengthening.

– Scapula stabilizing strengthening.

– More effective anterior atraumatic subluxation

and posterior instability.

Indications for early surgeryIndications for early surgery

• Soft tissue (ruptured cuff)

• Displaced fracture of greater tuberosity

– Superior and posterior displacement on AP radiograph.

• Glenoid rim fracture

– Incongruity and inadequate glenoid arch

• Special problems

– High demand work or sports.

Posterior dislocationsPosterior dislocations

• Reduction

– Supine position.

– Longitudinal and lateral traction.

– Head lifted anteriorly.

– Open reduction through deltopectoral

approach.


• Post reduction care– Sling immobilization.

– Brace in abduction, external rotation and extension in unstable cases.

• Early surgery– Tuberosity fracture.

– Glenoid rim fracture.

– Irreducible dislocation.

– Open dislocation.

– Unstable reduction.


• Chronic posterior dislocations

– ? Surgery in older patient.

– Sometimes there is a tuberosity transfer or

arthroplasty.

Recurrent instabilityRecurrent instability

• Recurrent atraumatic instability

– Minimal trauma.

– No humeral head defect.

– No tuberosity fracture.

– No glenoid lip fracture.

Recurrent instabilityRecurrent instability

• Recurrent atraumatic instability

– Thin compliant capsule.

– Flat glenoid fossa.

– Poor neuromuscular control.

– Poor humeral head centering.

Recurrent atraumatic instabilityRecurrent atraumatic instability

• Loss of midrange stability

• Multi directional

• Many factors may be developmental

– Likely to be bilateral and familial

• AMBRII


• Discomfort and dysfunction.

• ADL

• Minor injury or period of disuse may be

present.

• Reduces spontaneously.

• Progressively easy development of

symptoms.


• Physical examination.

– Patient demonstrate jerk test and inferior

subluxation.

– Laxity test.

– Stability tests.

– Strength tests.


• Radiographs

– Usually no bony pathology.

– Sometimes translation of humeral head on

glenoid.

– Hypo plastic or dysplastic glenoid.

• Arthroscopy

– Drive through sign.

Recurrent traumatic instabilityRecurrent traumatic instability

• Injury of sufficient magnitude.

• Determine definition of original injury.

• Inquire subsequent episodes of instability.

• Problems throwing overhand, sleeping,

hand behind head, lifting bucket of water.


• 14 to 34yrs

– glenoid labrum, glenoid rim and postero

lateral humeral head.

• Older than 35yrs

– greater tuberosity displaced and rotator cuff

(subscapularis).

• TUBS


• Apprehension test

confirm impression

obtained from

history.


• Pain relieves with

relocation.


• Radiographs

– Look for head and glenoid defects.

– CT scans for bony defects.

– MR arthrography for labrum, ligament and

rotator cuff injury.

• Electromyography


• Arthroscopy

– Classification of anterior labrum Bankhart

lesions.

– Definition of type of lesion.

– Diagnosis of SLAP lesions.

Recurrent instability treatmentRecurrent instability treatment

• Non operative

– Strong muscle contraction

• Stabilize humeral head in glenoid (mass effect)

– Strong muscle action

• Centralize humeral head on glenoid.

– Optimal neuromuscular control

• Rotator cuff, deltoid, pectoralis and scapular

muscles.

Recurrent instability treatmentRecurrent instability treatment

• Non operative

– Of particular benefit

• AMBRI

• Children

• voluntary instability

• posterior instability

• supranormal range required like gymnasts

Operative management Operative management

traumatic anterior instabilitytraumatic anterior instability

• Where original anatomy has been

disrupted

• Redislocation most likely

– Reduced glenoid depth and width.

• Procedures

– Capsular labral reconstruction.

– Coracoid transfer.

– Open or Arthroscopic.

Operative management of Operative management of

posterior posterior instabliltyinstablilty

• Multifactorial and complex

• Posterior soft tissue repairs.

• Rotational osteotomy of humerus.

Operative treatment of Operative treatment of

atraumatic instabilityatraumatic instability

• Concavity compression optimized

– Muscle strengthening and neuromuscular control.

• Mechanical problem must be identified.

• Surgery

– Deepening the glenoid through capsulolabralreconstruction

• Open and arthroscopic techniques.

Operative treatment of Operative treatment of

atraumatic instabilityatraumatic instability

Superior Superior labrallabral lesions (SLAP)lesions (SLAP)

• Fall on outstretched hand with humeral

head compression over labrum.

• Deceleration injury with sudden pull on

LHB.

• Pain with stress on LHB.

• MR arthrography.

• Arthroscopic repair.

Superior Superior labrallabral lesions (SLAP)lesions (SLAP)

dr. js kirsten louis leipoldt medical centre room 333, broadway

Documents