Shoulder Instability

Shoulder InstabilityDR Harpreet Singh BhatiaDMCH,Ludhiana,Punjab

DEFINITION:

Instability:Inability to maintain the humeral head in the glenoid fossa.Includes a spectrum of disorders

Dislocation Complete loss of glenohumeral articulationSubluxation Partial loss of glenohumeral articulation with symptomsLaxity Incomplete loss of glenohumeral articulation unassociated with pain

STABILITY Static FactorsArticular CongruenceArticular VersionGlenoid LabrumCapsule and Ligament

Dynamic FactorsRotator CuffBiceps TendonScapulothoracic MotionNegative PressurePropioception

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OSTEOLOGYGlenoid fossaPear shaped7 deg. of retroversion5 deg. of sup tiltGlenoid version30o anteriorHumerusNeck-shaft 130o to 140oRetrotorsion 30o

Normal glenoid is about 7 degrees retroverted

If the retroversion is excessive, it leads to posterior instability of shoulderSTATIC FACTORS

GLENOHUMERAL JOINTHumeral head 3x larger than glenoid fossaBall and socket with translation3 degrees of freedomFlex/ExtAbd/AddInt/Ext rotPlus Cricumduction

GLENOID LABRUMStatic stabilizercontributes 20% to GH stabilityFibro cartilaginous tissueDeepens glenoid(50%)3purposes:Inc. surface contact areaButtressAttachment site for GH ligaments

The labrum increases the superoinferior diameter of the glenoid by 75% and the anteroposterior (AP) diameter by 50%

CAPSULE AND LIGAMENTS CapsuleAttached medially glenoid fossalaterally to anatomical neck of humerusAnt cap thicker than post.2-3 mm of distractionLittle contribution to joint stabilityStrengthened by GHLs and RC tendons

LIGAMENTS

GLENOHUMERAL LIGAMENTS (Superior, Middle , Inferior)SGHLO = tubercle on glenoid just post to long head bicepsI = upper end of lesser tubercleResists inf. subluxation and contributes to stability in post and inf. directions

MGHLO= sup glenoid and labrumI = blends with subscapularis tendonLimits ant. instability especially in 45 deg abduction position Limits ext rotation

IGHLO= ant. glenoid rim and labrumI= inf. aspect of humeral articular surface and anatomic neck3 bands, anterior, axillary and posteriorActs like a sling ,the most important single ligamentous stabilizer .Primary restraint is at 45-90 deg abduction.

Coracoacromial ligamentsecondary stabilizer.Coracohumeral ligamentContribute to restraining inferior subluxation with arm at side,

Dynamic FactorsRotator CuffBiceps TendonNegative PressureScapulothoracic motionProprioception

ROTATOR CUFFCompression enhances conformityGreater than static stabilizersCoordinated contractions/steering effectSupraspinatus most important Dynamization

Biceps long head, Deltoid secondary stabilizer head depressor Periscapular Muscles help position scapula and orient glenohumeral joint contributes compressive force across joint

SCAPULOTHORACIC MOTION2:1 glenohumeral to scapulothoracic motionScapulothoracic muscle (trapezius, serratus anterior, teres major, levator scapulae)less stable platform

NEGATIVE INTRA-ARTICULAR PRESSURE-42 cm H2O in cadaverSecondary to high osmotic pressure in interstitial tissuesOnly clinically important in the arm at rest in adductionLost with lax capsule or defect

INSTABILITYClassification:FrequencyCause DirectionDegree

Classification of instability

SPECTRUM Traumatic Microtrauma Atraumatic

Less laxity More laxity

Unidirectional Multidirectional

PATHOANATOMY OF SHOULDERINSTABILITYLaberal Lesions Bankart Reverse Bankart SLAP lesionsCapsular 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%

BANKART LESION-labral tear at anterior half of glenoid rim

Reverse Bankart lesion

Anchor used for repair

HILL-SACHS LESION This is a defect in the posterolateral aspect of the humeral head.

Hill Sach Lesion

EVALUATION OF INSTABILITYHistoryAgeTrauma-DurationAssociated Pain Sports, throwing or overhead activitiesVoluntary subluxationClunk or knockFear-Limitation of MovementsHx dislocationsand energy associatedHx 1st dislocation or injurySubsequent dislocations/ subluxations

Physical Examination Inspection Palpation ROM Winging Neurovascular testing Generalized ligamentous laxity Instability tests

Sulcus signDrawer testsLoad & Shift test

Apprehension testJobes Relocation Jerk testFulcrum Grade = 1 - 4

DIAGNOSISX-raysCT ScanMRIArthroscopy

RADIOLOGYX-RaysIdentify Bankart or Hill-Sachs Lesion

AP VIEW

Normal Shoulder AP view

Axillary View

Scapular Y-View

Stryker viewHumeral Head Defect

Apical Oblique view

Glenoid rim lesion

West Point Axillary view Anteroinferior glenoid rim

ANTERIOR DISLOCATION 97% of recurrent dislocation abduction, extension and external rotationsubcoracoid subglenoidsubclavicular Associated Injuries: Fractures Head & Neck Rotator Cuff Tears > 40 y/o = 30 % > 60 y/o = 80%

Neurologic InjuryAxillary nerve10-25% incidence 1st time.2-5% in recurrent dislocatorsTx: watchful expectancyPoor prognosis if no recovery by 10 wksVascular Injury Axillary artery 2nd part thoracoacromial trunk

POSTERIOR DISLOCATION

Incidence: < 5% all shoulder dislocations 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

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TREATMENT Non Operative Immobilization Protection Rehabilitation 70-90% improve Functional disability improved Instability not eliminated

Operative Management

Overall 50-95 % successHigher recurrence vs ant. instability procedures

Soft Tissue Procedures Posterior Capsulorrhaphy Reverse Putti-Platt (IS Capsular Tenodesis) McLaughlin Bone Procedures

Posterior Glenoid OsteotomyPosterior Bone Block

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 RepairBankartModified Bankart Subscapularis Procedures Putti-Platt Magnuson-Stack Coracoid Transfer Procedures Bristow Latarjet

TREATMENT OPTIONSTYPE OF INSTABILITYPREFERRED SURGERYTraumatic anterior, with Bankart LesionOpen / arthroscopic Bankart repairTraumatic anterior , with no labral lesion, just capsular laxityOpen / arthroscopic capsular imbricationAMBRI lesionsLateral capsular shift( modified Neer and Foster ) with closure of rotator intervalRecurrent posterior dislocation in association with a reverse Hill-Sachs lesionmodified McLaughlin procedure Head defect > 30 45 % > 45 % Acute disimpaction / Weber osteotomyProsthetic replacementGlenoid defectBristow Latarjet coracoid transferStructural bone graft

Procedures

ProcedureDescriptionResultsNeers CapsulorrraphyPosterior capsular tighteningGenerally unsatisfactory, upto 50 % recurrenceStaple capsulorraphyTightening done with staplesSmall study groupTieborne and bradley procedureCapsular Imbrication with a horizontal T approachUpto 20 % recurrenceHawkins and Janda procedureSubscapularis advancement and shortening0 5 % recurrenceRockwood Glenloid Plasty with Biceps Tenodesis to the posterior capsuleCombined bony and soft tissue procedureNot often done

OPEN BONY PROCEDURES FOR ANTERIOR INSTABILITY

Bristow procedure

Latarjet procedure

Helfet first described the Bristow procedure in 1958 and named it after his late mentor .

In the Bristow procedure and its variants, the coracoid process is transferredthrough the subscapularis tendon as a method of treating recurrent anterior instability of the shoulder.

1) The coracoid tip is transferred to the anteroinferior glenoid neck and likely serves as a bone block in front of the humeral head. The transferred short head of the biceps and coracobrachialis are placed so as to produce a strong dynamic buttress across the anterior and inferior aspects of the joint when the shoulder is in the vulnerable abducted and externally rotated position. The transfer was held in place bysuturesthrough the conjoined tendon and subscapularis.

2) Latarjet described a similar procedure in 1954, in which he transferred the tip of the coracoid along with the conjoined tendon through a horizontal slit in the subscapularis and fixed it with a screw

The procedure involves transfer of the coracoid with it's attached muscles to the deficient area over the front of the glenoid.

This replaces the missing bone and the transferred muscle also acts as an additional muscular strut preventing further dislocations.

The procedure has a high success rate (recurrence rate of less than 1%4) and this is due to the triple effect described by Patte.

These are: Increase or restore the glenoid contact surface area;

The conjoint tendon stabilises the joint when the arm is abducted and externally rotated, by reinforcing the inferior subscapularis and anteroinferior capsule

Repair of the capsule. This triple effect is why the Latarjet is such a successful procedure.

Latarjet procedure

AMBRI Lesions-Idea of managementPrimary treatment nonoperative

Operative management recommended for patients who have continued pain or disability despite an adequate rehabilitation

The gold standard is open stabilization

Capsular shift( modified Neer and Foster )

OPEN ANTERIOR PROCEDURES FOR POSTERIOR INSTABILITY

McLaughlin procedure

Neers modification of McLaughlin procedure

McLaughlin technique

subscapularis

Neers modification

Putty Platt Operation

Surgical procedure for stabilizing the glenohumeral joint after recurrent anterior shoulder dislocations. The subscapularis tendon is detached near its insertion on the humerus, the joint opened, and the stump of the tendon on the lesser tuberosity is sutured to the glenoid labrum.

Sometimes the procedure is combined with reattachment of the glenoid labrum.

Technically an easy procedure

Disadvantages:

The Putti-Platt procedure is not to be performed on throwers because it can reduce the range of movement in the shoulder.

30 35 % incidence of late OA

Magnuson Stack procedure

ADVANTAGES AND DISADVANTAGES OF ARTHROSCOPIC STABILIZATIONADVANTAGES DISADVANTAGES-Improved cosmesis -Technically demanding -Shorter operative time -Difficult in revision case-Short hospital stay -Difficult in altered anatomy-Decreased morbidity -Cannot address bony defect-Decreased complication-Lower cost

PHASES OF REHABILITATIONPhase I Rest and immobilization. Pain control with nonsteroidal anti-inflammatory drugs and ice applied to the shoulder Phase II Isometric strengthening Isotonic strengthening. Begin exercises with shoulder in adducted, forward- flexed position, progressing to abducted position Phase III Endurance building along with strengthening exercises. Goal: the patient reaches 90% strength in the injured shoulder compared with the uninjured shoulder Phase IV Increase activity to sport- or job-specific activities

THANKS