Shoulder InstabilityShoulder Instability

April 2012April 2012

RyanRyan

ShoulderShoulder

The shoulder is the most mobile joint in the bodyThe shoulder is the most mobile joint in the body ItIt’’s a minimally constrained articulation that must balance s a minimally constrained articulation that must balance

mobility with stabilitymobility with stability Not always successful, as it is the most likely joint to Not always successful, as it is the most likely joint to

dislocatedislocate

Laxity vs. InstabilityLaxity vs. Instability

• Laxity: Asymptomatic passive translation of humeral head on the glenoid

• Instability: Excessive symptomatic translation of humeral head on glenoid duringactive motion

Definition of TermsDefinition of Terms

• Direction: Anterior vs. Posterior vs. MDI

• Timing: Acute vs. Chronic

• Frequency: Single vs. Recurrent

• Etiology: Traumatic vs. Atraumatic

• Degree: Subluxate vs. Dislocate

• Volition: Voluntary vs. Involuntary

The Stable ShoulderThe Stable Shoulder

Static RestraintsStatic Restraints– BoneBone

GlenoidGlenoid HumerusHumerus

– LigamentsLigaments– LabrumLabrum– CapsuleCapsule– Negative pressureNegative pressure– Adhesion/cohesionAdhesion/cohesion

Dynamic Dynamic RestraintsRestraints– Rotator CuffRotator Cuff

Concavity Concavity compressioncompression

– BicepsBiceps– DeltoidDeltoid– Scapula RotatorsScapula Rotators

Static: BoneStatic: Bone

GlenoidGlenoid– Articular VersionArticular Version

30 anterior on Chest 30 anterior on Chest wallwall

3 upward tilt3 upward tilt 7 retroversion (25% 7 retroversion (25%

of people of of people of anteversion 2-10)anteversion 2-10)

Bare spot in the Bare spot in the center and more center and more cartilage in cartilage in periphery (increases periphery (increases the depth)the depth)

– Bone lossBone loss FractureFracture DysplasiaDysplasia

Static: BoneStatic: Bone HumerusHumerus

– VersionVersion 130 neck shaft angle130 neck shaft angle 30 retroversion30 retroversion

– Articular SurfaceArticular Surface More of sphere in the center and More of sphere in the center and

elliptical in the peripheryelliptical in the periphery– In any position, there is only 25-In any position, there is only 25-

30% of the humeral head in 30% of the humeral head in contact with the glenoidcontact with the glenoid

Importance of soft tissue for Importance of soft tissue for stabilitystability

– CongruityCongruity Almost a perfect match with Almost a perfect match with

glenoid (<3mm)glenoid (<3mm) Congruity less important than Congruity less important than

total surface areatotal surface area– Hill-Sachs Hill-Sachs

ReverseReverse EngagingEngaging

Static RestraintsStatic Restraints

LabrumLabrum– Anchor for capsule & Anchor for capsule &

ligamentsligaments– Deepens the Deepens the

concavity of the concavity of the socketsocket

Increases depth of Increases depth of socket by 50% (5-socket by 50% (5-9mm)9mm)

– Increases surface Increases surface areaarea

– BumperBumper Resection decreases Resection decreases

resistance to resistance to translation by 20%translation by 20%

Static RestraintsStatic RestraintsCapsuloligamentsCapsuloligaments

Coracohumeral ligamentCoracohumeral ligament– Primary restraint to inferior Primary restraint to inferior

translation of the ADDucted arm translation of the ADDucted arm and to ERand to ER

SGHLSGHL – Primary restraint to ER in Primary restraint to ER in

ADDucted or slightly abducted armADDucted or slightly abducted arm– Primary restraint to inferior Primary restraint to inferior

translation in the ADDucted armtranslation in the ADDucted arm MGHLMGHL (absent in 30-40%) (absent in 30-40%)

– Primary stabilizer to anterior Primary stabilizer to anterior translation with the arm abducted translation with the arm abducted to 45 (45-90)to 45 (45-90)

IGHLC- A&P bands, hammockIGHLC- A&P bands, hammock– Primary stabilizer for anterior and Primary stabilizer for anterior and

inferior instability in abductioninferior instability in abduction– Posterior band in flexion/adduction Posterior band in flexion/adduction

to posterior instabilityto posterior instability

Static RestraintsStatic Restraints

Adhesion/cohesionAdhesion/cohesion– Attraction of joint fluid to itself and to the Attraction of joint fluid to itself and to the

articular surface articular surface – Cover slip to slideCover slip to slide

Suction CupSuction Cup– The glenoid and labrum act as a suction The glenoid and labrum act as a suction

cupcup Negative joint pressureNegative joint pressure

– Analogous to pulling on the plunger of a Analogous to pulling on the plunger of a plugged syringeplugged syringe

– Venting the joint allows 55% increase in Venting the joint allows 55% increase in anterior translationanterior translation

Dynamic RestraintsDynamic Restraints

Rotator CuffRotator Cuff– Concavity-CompressionConcavity-Compression

Enhances the conformity Enhances the conformity of the joint and increases of the joint and increases the force required to the force required to translatetranslate

– Could be more important Could be more important than ligament restraintsthan ligament restraints

– RC blend into ligaments RC blend into ligaments and could provide dynamic and could provide dynamic restraints through themrestraints through them

– Importance of RC Importance of RC strengthening in Rehabstrengthening in Rehab

– Anterior-superior escape in Anterior-superior escape in cuff tear arthropathy (CTA)cuff tear arthropathy (CTA)

Dynamic RestraintsDynamic Restraints

BicepsBiceps– Difficult to determine Difficult to determine

its actual its actual contributioncontribution

– Many studies with Many studies with differing resultsdiffering results

– ? Function as a ? Function as a humeral head humeral head depressordepressor

DeltoidDeltoid– Increase activation in Increase activation in

unstable shoulderunstable shoulder

Dynamic StabilityDynamic Stability

Scapular RotatorsScapular Rotators– Trapezius, Rhomboids, Lat, Trapezius, Rhomboids, Lat,

Serratus, LevatorSerratus, Levator– 2:1 ratio of GH motion to 2:1 ratio of GH motion to

Scapulothroacic motion Scapulothroacic motion – Provide stable platform Provide stable platform

beneath humeral headbeneath humeral head– Importance rehab to include Importance rehab to include

scapular rotatorsscapular rotators ProprioceptionProprioception

– Mechanoreceptors send Mechanoreceptors send message in reflex arc to message in reflex arc to control shouldercontrol shoulder

– Increased hand position Increased hand position error in pts with MDIerror in pts with MDI

– Surgery improves GH Surgery improves GH proprioceptionproprioception

Breakdown of StabilityBreakdown of Stability

MinimalMinimal loads: loads: – Negative intraarticular pressureNegative intraarticular pressure– Adhesion/CohesionAdhesion/Cohesion– Suction CupSuction Cup

ModerateModerate loads, Mid-range: loads, Mid-range: – Concavity-compressionConcavity-compression– Labrum Labrum – Scapulothoracic Rhythm & ProprioceptionScapulothoracic Rhythm & Proprioception

LargeLarge loads, End-range: loads, End-range: – IGHLIGHL

Pathoanatomy of Instability: Pathoanatomy of Instability: Bankart LesionBankart Lesion

““Essential lesionEssential lesion”” Separation of Separation of

inferior inferior capsulolabral capsulolabral complex from complex from glenoid neckglenoid neck– Broca and Hartmann Broca and Hartmann

1890 – see figure1890 – see figure– Perthes 1906Perthes 1906– Bankart 1923, 1939Bankart 1923, 1939

Bankart Lesion:Bankart Lesion:

1. Disrupts the concavity compression1. Disrupts the concavity compression2. Eliminates the bumper2. Eliminates the bumper3. Decreases depth by 50%3. Decreases depth by 50%4. Detaches capsuloligamentous structures4. Detaches capsuloligamentous structures5. May eliminate the negative intraarticular 5. May eliminate the negative intraarticular

pressurepressure

Pathoanatomy of Instability: Pathoanatomy of Instability: Capsular injuryCapsular injury

Bankart Less often considered the all-Bankart Less often considered the all-or-none or-none ““Essential lesionEssential lesion”” but still the but still the most common lesion: 62-97%most common lesion: 62-97%– Simulation of Bankart results in only Simulation of Bankart results in only

minimal increase in translationminimal increase in translation– Plastic deformity of the capsule is requiredPlastic deformity of the capsule is required

ALPSA: anterior labral periosteal ALPSA: anterior labral periosteal sleeve avulsionsleeve avulsion

HAGL/BHAGL: humeral avulsion of the HAGL/BHAGL: humeral avulsion of the glenohumeral ligamentsglenohumeral ligaments

GLAD: glenolabral articular disruptionGLAD: glenolabral articular disruption

Pathoanatomy of Instability:Pathoanatomy of Instability:

ALPSA LesionALPSA Lesion

Pathoanatomy of Instability:Pathoanatomy of Instability:

HAGL LesionHAGL Lesion

Pathoanatomy of Instability: Pathoanatomy of Instability: Bone LossBone Loss

HumerusHumerus– Hill-Sachs or Reverse Hilll-Hill-Sachs or Reverse Hilll-

SachsSachs– 60-90% of primary anterior 60-90% of primary anterior

dislocationsdislocations– 90-100% in recurrent 90-100% in recurrent

dislocationsdislocations– 25% of subluxations25% of subluxations– Larger defectsLarger defects

Longer dislocationsLonger dislocations RecurrentRecurrent InferiorInferior

– >30% defect may lead to >30% defect may lead to recurrent instabilityrecurrent instability

Tendon ( Remplissage)Tendon ( Remplissage) AllograftAllograft ReplacementReplacement

Pathoanatomy of Pathoanatomy of Instability: Instability: Bone LossBone Loss

GlenoidGlenoid– Bony BankartBony Bankart– Erosion from Recurrent Erosion from Recurrent

dislocationdislocation– Glenoid defects in 22% acute Glenoid defects in 22% acute

dislocations and 73% of dislocations and 73% of patients with recurrentpatients with recurrent

– Defects < 15% repair Defects < 15% repair labrum/capsulelabrum/capsule

– Bigliani – loss of > 25% Bigliani – loss of > 25% warrants bony reconstructionwarrants bony reconstruction

– Burkhart – inverted pear Burkhart – inverted pear glenoid requires bony glenoid requires bony reconstructionreconstruction

61% recurrence with inverted 61% recurrence with inverted pear or engaging Hill Sachs vs pear or engaging Hill Sachs vs 4% recurrence without4% recurrence without

Measure bare spot to anterior Measure bare spot to anterior rim.rim.

ReconstructionReconstruction– Iliac crestIliac crest– Coracoid (Latarjet)Coracoid (Latarjet)– Lateral aspect of tibial plafondLateral aspect of tibial plafond

Provencher, Arthroscopy 2009

Pathoanatomy of Instability: Pathoanatomy of Instability: Associated InjuriesAssociated Injuries

Rotator cuff tearRotator cuff tear– Under 30 rareUnder 30 rare– Over 40Over 40

85%85%

Nerve injuriesNerve injuries– Axillary: up to Axillary: up to

33%33%– MusculocutaneouMusculocutaneou

s s

Clinical EvaluationClinical Evaluation

• Etiology: Traumatic vs. Atraumatic

• Direction: Ant vs. post vs. MDI

• Timing: Acute vs. chronic

• Frequency: Single vs. recurrent

• Degree: Sublux vs. Dislocate

• Volition: Voluntary vs. involuntary

Clinical EvaluationClinical Evaluation

HistoryHistory– Acute vs. ChronicAcute vs. Chronic– Isolated vs. recurrentIsolated vs. recurrent– Dislocation vs. subluxationDislocation vs. subluxation– DirectionDirection– Past treatmentPast treatment

PEPE– ROMROM– StrengthStrength– Neurovascular examNeurovascular exam– AtrophyAtrophy– WingingWinging– SulcusSulcus– Load and ShiftLoad and Shift– ApprehensionApprehension– RelocationRelocation– JerkJerk

Pts w/ bony defects should have marked Pts w/ bony defects should have marked apprehension and at lesser angles of apprehension and at lesser angles of abduction and ERabduction and ER

Radiographs and/or CTRadiographs and/or CT EUAEUA ArthroscopyArthroscopy

West Point view

Prone, 25 degree from midline, directed through axilla

Itoi – correlated West Point view with CT for glenoid bone loss

Axillary view underestimates

Hill Sachs evaluation Stryker notch view

– Hand to head, elbow up

– Beam angle up 10 degrees

– Centered over coracoid

CT preferred over MRI– MRI underestimates

bone defect

Anterior DislocationAnterior Dislocation

85-90% of 85-90% of dislocationsdislocations

TreatmentTreatment– Prompt atraumatic Prompt atraumatic

reductionreduction– ImmobilizationImmobilization

Risk of RecurrenceRisk of Recurrence– Age (<30)Age (<30)– Activity levelActivity level– Compliance with rehabCompliance with rehab– Contralateral shoulder Contralateral shoulder

instabilityinstability– Bony defectsBony defects

Emergent Management

Immobilization (duration)No change in outcome ? (Hovelius et al., 1983; Rowe et al. 1961)

One week (Kazar et al., 1969)

Three weeks (Kiviluoto et al., 1980; Stromsoe et al 1980)

Dependent on age ? >40 1 week<40 3 weeks

Emergent Management

Immobilization (position)Internal rotation and adduction (sling)Labrum anatomically better position in ER (Itoi et al, 2001)

Emergent Management

Immobilization (position)Clinical follow-up for 15 months (Itoi et al., 2003)

No recurrent dislocation with ER immobilization30% dislocation with IR immobilization0% vs. 45% for patients younger than 30

Goals of RehabilitationGoals of Rehabilitation

Return dynamic stabilizers to Return dynamic stabilizers to functional statefunctional state

Protect healing of static stabilizersProtect healing of static stabilizers Minimal immobilizationMinimal immobilization Early ROM, avoid EREarly ROM, avoid ER Strengthening in plane of scapulaStrengthening in plane of scapula Bracing/harnessing for return to Bracing/harnessing for return to

sportssports

Anterior dislocationAnterior dislocation

SurgerySurgery– Early vs. LateEarly vs. Late

<30 y/o surgery may be <30 y/o surgery may be first linefirst line

– Open vs. ArthroscopicOpen vs. Arthroscopic Open still Open still ““gold gold

standardstandard”” Reader bewareReader beware

– Some open techniques Some open techniques not anatomic (high not anatomic (high OA)OA)

– Early scopic studies Early scopic studies with poor techniques with poor techniques and implantsand implants

Scope vs. OpenScope vs. Open

ArthroscopicArthroscopic– Minimizes dissectionMinimizes dissection– Decreased damage Decreased damage

to soft tissuesto soft tissues SubscapSubscap

– Earlier RehabEarlier Rehab– Better ROMBetter ROM– Hard to over tightenHard to over tighten– Better visulaizationBetter visulaization– Treat other Treat other

pathologypathology– Learning CurveLearning Curve– OutpatientOutpatient

OpenOpen– Gold standardGold standard– Initially lower Initially lower

recurrencerecurrence Possibly over Possibly over

constrainedconstrained– Still required forStill required for

Large bony defectsLarge bony defects HAGL?HAGL? Capsular Capsular

insufficiencyinsufficiency RevisionRevision

– CosmesisCosmesis– OR timeOR time– InpatientInpatient

Scopic vs. OpenScopic vs. Open

Open (recurrence)Open (recurrence)– Putti-Platt 3.0%Putti-Platt 3.0%– Mag-StackMag-Stack

4.14.1– Eden-Hybbinette 6.0Eden-Hybbinette 6.0– GallieGallie 2.92.9– DuTolt & Roux 2.0DuTolt & Roux 2.0– BristowBristow 1.71.7– BankartBankart 3.33.3– Capsulorrhaphy 3.4Capsulorrhaphy 3.4

– Classic BankartClassic Bankart Rowe and BankartRowe and Bankart

– 96% success96% success

Scopic AnchorsScopic Anchors– BacillaBacilla 7%7%– GartsmanGartsman 8 8– ColeCole 00– KimKim 44– KimKim 1010– AbramsAbrams

6.66.6– MazzoccaMazzocca

1111– Fabbriciani (Fabbriciani (’’04)04) 00

– Recent scopic anchor Recent scopic anchor technique also with technique also with 96% success96% success

Arthroscopy, 2010

PosteriorPosterior

Acute posteriorAcute posterior– <5%<5%– Unrecognized in 50-Unrecognized in 50-

80% of patients initially80% of patients initially ChronicChronic

– > 6weeks locked out > 6weeks locked out the backthe back

Volitional RecurrentVolitional Recurrent– Habitual dislocator Habitual dislocator

(psych issues)(psych issues)– Voluntary (can Voluntary (can

selectively fire muscles)selectively fire muscles) May become May become

involuntaryinvoluntary Dysplastic RecurrentDysplastic Recurrent

– Hypoplasia, glenoid or Hypoplasia, glenoid or humeral retroversionhumeral retroversion

PosteriorPosterior TreatmentTreatment

– NonopNonop Rehab focusing on Rehab focusing on

infraspinatus/teres infraspinatus/teres minor/posterior minor/posterior deltoid/scapuladeltoid/scapula

63-68% success63-68% success– SurgerySurgery

OPEN vs. ScopicOPEN vs. Scopic Capsulorrhaphy/Capsulorrhaphy/

shiftshift Reverse bankartReverse bankart Bone blockBone block Glenoid osteotomyGlenoid osteotomy Infraspinatous Infraspinatous

Capsular tenodesisCapsular tenodesis– ResultsResults

85-91% success85-91% success

MDIMDI

Subluxate or dislocate in Subluxate or dislocate in multiple directions, with multiple directions, with concurrent reproduction of concurrent reproduction of symptoms in at least 2 symptoms in at least 2 directions, one being directions, one being inferiorinferior

Symptoms usually in mid-Symptoms usually in mid-range of motion (ADLrange of motion (ADL’’s)s)

Positive Sulcus with Positive Sulcus with symptomssymptoms

PathologyPathology– Widened Rotator IntervalWidened Rotator Interval– Redundant inferior capsuleRedundant inferior capsule– Collagen abnormality?Collagen abnormality?– MechanoreceptorMechanoreceptor– Abnormal muscle controlAbnormal muscle control

MDIMDI

Nonop – RehabNonop – Rehab– Rockwood 88% success Rockwood 88% success

raterate– Must prove that they will Must prove that they will

be compliantbe compliant SurgerySurgery

– Open or scopic inferior shiftOpen or scopic inferior shift ScopicScopic

– Posterior capsulePosterior capsule– Anterior capsuleAnterior capsule– Rotator IntervalRotator Interval

– Post-op Cast or bracePost-op Cast or brace ResultsResults

– Pollack 94%Pollack 94%– BremsBrems 85%85%– Hawkins Hawkins 60%60%– SavoieSavoie 88%88%– GartsmanGartsman 94%94%– McIntyreMcIntyre 95%95%

Questions?Questions?