dr. js kirsten louis leipoldt medical centre room 333, broadway
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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
Historical overviewHistorical overview
• Treatment of acute
traumatic dislocation
– Hippocrates: Six
different techniques
– Kocher - 1817
– Milch - 1938
Historical overviewHistorical overview
• Posterior
glenohumeral
instability - 1839
– Diagnosis without x-
rays
– X-rays discovered late
1800’s
Historical overviewHistorical overview
• 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
Relevant AnatomyRelevant Anatomy
• Coracoacromial arch
– Coracoid serves as
landmark during
surgery.
Relevant AnatomyRelevant Anatomy
• Humeral scapular
motion interface.
– Not moving: Deltoid,
coracoid muscles,
acromion,
coracoacromial
ligament.
– Moving: Rotator cuff,
long head of biceps,
humeral tuberosities.
Relevant AnatomyRelevant Anatomy
• Rotator cuff
– Subscapularis
– Rotator interval
– Supraspinatus
– Infraspinatus
– Long head of biceps
Relevant AnatomyRelevant Anatomy
• Scapulohumeral
ligaments
– Superior glenohumeral
ligament, middle
glenohumeral
ligament, inferior
glenohumeral
ligament.
Relevant AnatomyRelevant Anatomy
• Scapulohumeral ligaments
– Relaxed throughout most of range of motion.
– Play role primary in positions near extremes
of motion.
– Proprioceptive function.
Relevant AnatomyRelevant Anatomy
• Glenoid labrum
– Consists of tense
fibrous tissue.
– Anteriorly continuous
with inferior
glenohumeral
ligament.
– Plays role in stability
Relevant AnatomyRelevant Anatomy
• 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
Mechanism of glenohumeral Mechanism of glenohumeral
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.
Mechanism of glenohumeral Mechanism of glenohumeral
stabilitystability
• Glenoid version
• Scapular
positioning
• Ligaments
• Rotator cuff.
Mechanism of glenohumeral Mechanism of glenohumeral
stabilitystability
• Glenoid version
• Scapular
positioning
• Ligaments
• Rotator cuff.
Mechanism of glenohumeral Mechanism of glenohumeral
stabilitystability
• Glenoid version
• Scapular
positioning
• Ligaments
• Rotator cuff.
Mechanism of glenohumeral Mechanism of glenohumeral
stabilitystability
• Glenoid version
• Scapular
positioning
• Ligaments
• Rotator cuff.
Mechanism of glenohumeral Mechanism of glenohumeral
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.
Net humeral joint reaction forceNet humeral joint reaction force
• 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.
Net humeral joint reaction forceNet humeral joint reaction force
• 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.
Ligamentous stabilizationLigamentous stabilization
• Act as countervailing
force.
– Compresses humeral
head into glenoid
fossa.
– Resists displacement.
Ligamentous stabilizationLigamentous stabilization
• 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
Types of GH instabilityTypes of GH instability
• 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.
Types of GH instabilityTypes of GH instability
Types of GH instabilityTypes of GH instability
• 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.
Types of GH instabilityTypes of GH instability
• 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.
Clinical findingsClinical findings
• Physical examination of anterior dislocated
shoulder
– Head palpable anteriorly.
– Hollow beneath acromion.
– Arm held in slight abduction and external
rotation.
Clinical findingsClinical findings
• 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
Clinical findingsClinical findings
• Radio graphic evaluation
– Demonstrate direction of dislocation.
– Associated fractures.
– Barriers to relocation.
Clinical findingsClinical findings
• Radio graphic
evaluation
– Note views oriented to
scapula.
• Antero posterior view in
plain of scapula.
Clinical findingsClinical findings
• Radio graphic
evaluation
– Note views oriented to
scapula.
• Scapular lateral view.
Clinical findingsClinical findings
• Radio graphic
evaluation
– Note views oriented to
scapula.
• Axillary view.
RadiographsRadiographs
Clinical findingsClinical findings
• 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
Associated injuries Associated injuries –– anterior anterior
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.
Associated injuries Associated injuries –– anterior anterior
dislocationdislocation
• Fractures
– Glenoid
– Humeral head
– Tuberosities
– Humeral neck fracture during attempted
closed reduction.
– Coracoid process
Associated injuries Associated injuries –– anterior anterior
dislocationdislocation
• Cuff tears
– Patients older than forty years
– Ultrasonography, arthrography, MRI
– Prompt repair
Associated injuries Associated injuries –– anterior anterior
dislocationdislocation
• Vascular injuries
– 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%.
Associated injuries Associated injuries –– anterior anterior
dislocationdislocation
• Vascular injuries
– 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.
Associated injuries Associated injuries –– anterior anterior
dislocationdislocation
• 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
anterior dislocationanterior dislocation
• 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
dislocationdislocation
• 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
anterior dislocationanterior dislocation
• Timing of reduction and analgesia
– Complete set of radio graphs.
– Rule out associated bony injuries.
– Early reduction.
Treatment of acute traumatic Treatment of acute traumatic
anterior dislocationanterior dislocation
• 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.
Treatment of acute traumatic Treatment of acute traumatic
anterior dislocationanterior dislocation
• 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.
Treatment of acute traumatic Treatment of acute traumatic
anterior dislocationanterior dislocation
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
anterior dislocationanterior dislocation
• Evaluation
– AP and lateral x-rays
– Neurological status
– Strength of pulse
– Bruits and expanding hematoma
– Rotator cuff integrity
Management after reduction of Management after reduction of
anterior dislocationanterior dislocation
• Protection
– Flexion to 90 degrees.
– External rotation to 0 degrees
– Three weeks.
– Cuff and deltoid isometrics
– Duration of immobilization reduced with
increasing age.
Management after reduction of Management after reduction of
anterior dislocationanterior dislocation
• 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.
Posterior dislocationsPosterior dislocations
• 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.
Posterior dislocationsPosterior dislocations
• 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
Recurrent atraumatic instabilityRecurrent atraumatic instability
• Discomfort and dysfunction.
• ADL
• Minor injury or period of disuse may be
present.
• Reduces spontaneously.
• Progressively easy development of
symptoms.
Recurrent atraumatic instabilityRecurrent atraumatic instability
• Physical examination.
– Patient demonstrate jerk test and inferior
subluxation.
– Laxity test.
– Stability tests.
– Strength tests.
Recurrent atraumatic instabilityRecurrent atraumatic instability
• 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.
Recurrent traumatic instabilityRecurrent traumatic instability
• 14 to 34yrs
– glenoid labrum, glenoid rim and postero
lateral humeral head.
• Older than 35yrs
– greater tuberosity displaced and rotator cuff
(subscapularis).
• TUBS
Recurrent traumatic instabilityRecurrent traumatic instability
• Apprehension test
confirm impression
obtained from
history.
Recurrent traumatic instabilityRecurrent traumatic instability
• Pain relieves with
relocation.
Recurrent traumatic instabilityRecurrent traumatic instability
• Radiographs
– Look for head and glenoid defects.
– CT scans for bony defects.
– MR arthrography for labrum, ligament and
rotator cuff injury.
• Electromyography
Recurrent traumatic instabilityRecurrent traumatic instability
• 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
Operative treatment of Operative treatment of
atraumatic instabilityatraumatic instability
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)
Superior Superior labrallabral lesions (SLAP)lesions (SLAP)
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