Shoulder instability Flashcards

Traumatic anterior shoulder instability posterior instability & post dislocation mutlidriecitonal instability Luxatio erecta

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1
Q

What is the epidemiology of TUBS ( traumatic unilateral dislocation with a bankart lesion requiring surgery)?

A
  • one of most common shoulder injuries
  • 1.7% annual rate in population
  • have a high recurrence rate that correlates with age at dislocation
  • uo to 80-90% in teenagers
  • mechanism
    • posteriorly directed force on the arm when the shoulder is abducted and externally rotated
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2
Q

What are the associated ligament injuries of TUBS?

A
  • Labral /cartilage lesions
    • Bankart lesion
      • avulsion of anterior labrum and anterior band of IGHL from anterior inferior glenoid
      • present 80-90% pts
    • Humeral avulsion of the glenohumeral ligament ( HAGL)
      • pts older than those w bankart lesion
      • assoc with high recurrence rate
    • Glenoid labral articular defect ( GLAD)
      • is a sheared off portion of articular cartilage along with labrum
    • Anterior labral periosteal sleeve avulsion (ALPSA)
      • can cause torn labrum to heal medially along medial glenoid neck
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3
Q

Name the assoc fx with TUBS?

A
  • Hill sach’s defect
    • is a chondral impaction injury in the posterosuperior humeral head secondary to contact with glenoid rim
    • present in 80% traumatic dislocations and 25% traumatic subluxations
    • not clinically signifcant unless engages the glenoid
  • Bony Bankhart lesion
    • fx of anterior inferior glenoid
    • present in 49% with recurrent dislocations
    • higher risk of failure of arthroscopic tx if not addressed
  • Greater tuberosity fx
    • assoc with anterior dislocation in pts >50 yrs
  • Lesser tuberosity fx
    • assoc with posterior dislocation
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4
Q

Name the assoc injuries of TUBS?

A
  • Ligament/tendon injuries- rotator cuff tears
  • Fractures
  • nerve injury
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5
Q

Describe the nerve injury in TUBS?

A
  • Axillary nerve
    • most often a transient neurapraxia of the axillary nerve
    • present in 5% patients
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6
Q

Describe the rotator cuff injuries in TUBS?

A
  • 30% of TUBS patients >40 yrs
  • 80% of TUBS pts >60 yrs
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7
Q

Describe the classification of TUBS?

A
  • anteriorposterior translation grading scheme
    • grade 0= normal glenohumeral translation
    • grade 1- humeral head translation up to rim
    • grade 2- humeral head translation over rim with spontaneous reduction once force withdrawn
    • grade 3- humeral head translation over glenoid rim with locking
  • Sulcus test grading scheme
    • Grade 1 acromiohumeral interval <1cm
    • Grade 2 acromiohumeral interval 1-2cm
    • Grade 3 acromiohumeral interval >2cm
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8
Q

What is the anterior shoulder static stability provided by?

A
  • Anterior band of Inferior glenohumeral lig
    • provides static restraint w arm at 90o Abduction and external rotation
  • Medial glenohumeral lig
    • provides static restraint with arm in 45o of Abduction and external rotation
  • Superior glenohumeral lig
    • provides static restraint with arm at side
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9
Q

What is the presentation of a pt with TUBS?

A
  • Traumatic event causing dislocation
  • feeling of instability
  • shoulder pain
    • caused by subluxation and excessive translation of humeral head on glenoid

O/E

  • apprehension test
    • pt supine w arm in 90/90 position
  • relocation sign
    • decrease in apprehension with post force applied to shoulder
  • Sulcus sign
    • tested with pt arm at side
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10
Q

What is seen on imaging in a pt with TUBS?

A

Xray

  • trauma series of shoulder
  • AP
  • Scapular Y
  • Axillary
  • West point- see glenoid bone loss
  • stryker view
    • shows hill- sachs lesions

CT

  • useful for evaulation of bony injuries

MRI

  • best for visualisation of labral tear
  • addition of intrarticular contrast- increases sensitivity and specificity
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11
Q

What is the tx of TUBS?

A

Nonoperative

  • Acute reduction, immobilisation and physio
    • first time dislocators
    • studies show immobilisation in ext rotation decrease recurrence - but poor pt compliance
    • strengthening of dynamic stabilisers - rotator cuff

Operative

  • Arthroscopic Bankart repair +/- capsular shift
    • first time traumatic shoulder dis w bankart lesion in pts <25 yrs/ high demand athletes
    • same oc as open but less pain and >motion preservation
  • Open Bankart repair +/- capsular shift
    • for glenoid defect >25% inverted pear
    • engaging Hill sachs lesion
    • humeral avulsion of glenohumeral lig
  • Brisow and Laterjet proceedure
    • bony defect with >20% glenoid deficiency
    • transfer of coracoid bone & conjoined tendon for sling effect
    • latarjet preformed more common
  • Putti-Platt/Magnuson-Stack-Boyd-Sisk
    • historical only-> over contrainst and arthrosis
  • Remplissage technique
    • engaging large Hill sach’s defect >25%
    • post capsule & infraspinatus tendon sutured into hill-sachs lesion
    • maybe preformed with bankart repair
  • Hill-sachs bony reconstruction
    • ​enaging hil sachs
    • allograft reconstruction
    • arthroplasty
    • rotational arthroplasty
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12
Q

Describe the epidemiology of posterior dislocation of shoulder?

A
  • Less common
  • often missed
  • 2-5% unstable shoulders
  • risk factors
    • bony abnormality
      • glenoid retroversion/hypoplasia
    • ligamentous laxity
  • Mechanism
    • trauma 50%
    • microtrauma
    • seizure/electric shock
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13
Q

What are the associated conditions of a posterior shoulder dislocation?

A
  • Avulsion of posteriof band of IGHL
  • posterior bankart lesion
  • reverse hill sachs lesions
  • posterior labral cyst
  • posterior glenoid rim fx
  • lesser tuberosity fx
  • large capsular pouch
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14
Q

what are the primary stabilsers in a posterior shoulder?

A
  • Posterior band of Inferior GH ligament
    • restraint to internal rotation
  • Subscapularis
    • restraint to external rotation
  • coracohumeral ligament
    • restraint to inferior translation of adducted arm & to ext rotation
    • restraint to posterior translation in flexed
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15
Q

What is the presentation of posterior dislocation of shoulder?

A
  • Hx of trauma w arm in flexed, adducted, internally rotated position

O/E

  • prominent posterior shoulder and coracoid
  • limited external rotation
  • shoulder locked in a internally rotated position
  • provocation test
    • posterior load and shift test
      • place pt supine w arm in neutral rotation 40-60o abduction and forward flexion, load humeral head and apply posterior translating forces noting subluxation
      • KIm test -see pic
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16
Q

What is seen on imaging of posterior dislocation of shoulder?

A
  • Ap - unrelible- lightbulb sign
  • axillary lateral - best view
  • CT analyse extent and location of bone loss in chronic dislocation >2-3 wks
  • MRI- evaluate for suspected Rotator cuff/ reverse hill sachs
17
Q

What is the tx of posterior dislocation of shoulder?

A

Non operative

  • ACUTE REDUCTION under sedation and immobilisation external rotation 4-6 wks

Operative

  • open or arthroscopic posterior labral repair ( banhart) and capsular shift
    • recurrent post dislocation, continued pain in bench press position
    • outcomes 80-85% success 5-7 yr fu after open
    • similar outcomes for arthroscopic
  • Open reduction w subscapularis and lesser tuberosity transfer to defect- modified McLaughlin)
    • chronic dislocation >6 months old
    • severe OA humeral head
    • collapse of humeral head
    • reverse hill sachs >50%
    • deltapectoral approach
    • lesser tuberosity & subscapularis advanced into bnoy defect on anterior humeral head ( orginal mclaughlin described subscap, neer added both)
    • iliac crest used for any bone graft

complx- stiffness, avn, oa

  • total shoulder arthroplasty
  • sig glenoid arthritis
18
Q

What are the complicaitons of posterior shoulder dislocations?

A
  • Recurrence 7-50%
  • Adhesive capsulitis
  • Generalised stiffness
  • overtightening of posterior capsule
    • -> anterior subluxation
  • Nerve injury
    • axillary/ suprascapular
19
Q

Describe multidirectional shoulder instability?

A
  • aka AMBRI
  • Atraumatic
  • Multidirectional
  • Bilateral - frequently
  • Rehabilitation - often responds to
  • Inferior capsular shift - best alternative to non op

peaks

  • 2-3rd decades

mechanism

  • microtrauma from overuse
    • seen with overhead throwing, swimers, gymnasts
  • Generalised ligamentous laxity
    • assoc w connective tissue disoders- Elhers danlos & marfan’s
20
Q

What is seen on pathoanatomy of multidirectional shoulder instability?

A
  • Hallmark of AMBI
    • Patulous inferior capsule- IGHL anterior & post bands
    • Rotator interval deficiency
  • Labral lesions or glenoid erosion can still occur from traumatic events
    • Bankart lesion us anterioinferior labral tear
    • Kim lesion is posterioinferior labral avulsion
21
Q

What is the presentation of multidirectional shoulder instability?

A
  • Pain
  • Instability
  • weakness
  • paraethesia
  • crepitus
  • shoulder instabilty during sleep

Tests

  • Sulcus test
    • assess rotator interval
  • apprehension/relocation test
  • load and shift test ( posterior instability)
  • hypermobility- Bieghton score , a score >6 = hypermobility assoc with marfan’s /ehler’s danlos syndrome
22
Q

What is seen on imaging of multidirectional shoulder instability?

A
  • Xray
    • complete trauma series- AP-IR, AP-ER, AP, Axillary, scapular Y
    • maybe normal in MDI
  • MRI
    • to fully evaluate shoudler
  • Arthroscopy
    • Drive thru sign
23
Q

What is the tx of multidirectional shoulder instability?

A

Non operative

  • Dynamic stabilisation by Physio
    • 1st line, majority of pts
    • 3-6 months regime
    • stregthening of dynamic stabilisers ( RC and periscapular muscles)
    • closed kinetic chain exercises are used early in rehab to process safely stimulate con-contraction of scapular & RC muscles

Operative

  • Capsular shift /stabilisation proceedure ( open vs arthroscopic)
    • failure of extensive nonop mx
    • pain & instability that interferes w ADL of psorts activities
    • CI- Voluntary dislocators
  • ​Capsular reconstruction ( allograft)
    • ​rare
24
Q

Can you describe the technical aspect of capsular shift/stabilisation procedure ( open or arthroscopic)?

A
  • Arthroscopy approach
  • must address capsule + Rotator interval
  • Inferior capsular shift ( capsule shifted superiorly)
  • Plication of redundant capsule in balanced fashion
  • **rotator interval closure **
    • produces the most significant decrease in rom in ext rotation with arm at the side
    • sutures superior and middle GHL together
    • address any anterior/posterior labral pathology if present
    • thermal capsulorrharphy - CI as complications including capsule ablation adn chondrolysis
  • post op rehab
    • 4-6 wks : shoulder immobiliser
    • 6-10 wks: ADLs with 45 degree limit on abduction/Ext rotation
    • 10-16 wks: gradual ROM
    • >16 wks : strengthening
    • >10 months: contact sports
25
Q

What are the complications of multidirectional shoulder instability surgery?

A
  • Subscapularis deficiency
    • caused by injury/failed repair
  • Loss of motion
    • overtighening or asymmetric tightening
    • leads to loss of Ext rotation
    • tx with z lengthening of subscapularis
  • Axillary n injury
    • iatrogenic injury w surgery ( abduction and ER moves axillary n away from glenoid)
    • Usually neurapraxia
  • Late arthritis
    • usually wear of posterior glenoid
    • may have internal rotation contracture
  • Recurrence
26
Q

What is luxatio erecta?

A
  • Inferior dislocation of glenohumeral joint
  • V rare, only 0.5%
  • commonly involves variable sized tearing of static glenohumeral ligaments
  • associated conditions
    • neurovascular injury- greatest incidence of all
27
Q

Describe the static glenohumeral restraints?

A
  • SGHL = to inferior translation at 0o of abduction
  • MGHL= to anterior and posterior translation in midrange of abduction
  • IGHL
    • posterior band- most important to Post subluxation at 90o flexion and IR
    • Anterior band- to ant/inf translation at 90o abduction and max ER - late cocking phase
    • **Superior band- most important static stabiliser about the joint
28
Q

How does someone present with luxatio erecta?

A
  • Shoulder pain
  • inabilty to move shoulder
  • neurovascular injury

O/E

  • Presents with arm overhead with shoulder in full abduction and elbow flexion
29
Q

What is seen in imaging of luxatio erecta?

A
  • Xray
    • inferior glenohumeral dislocation w arm fully abducted
  • MRI
    • post shoulder relocation to assess shoulder injuries
    • may have capsulolabral pathology
    • rotator cuff tears common
30
Q

What is the tx of luxatio erecta?

A

Non operative

  • Closed reduction and immobilisation- see pic- inline traction
    • gd response to non op tx
    • inactive elderly pts

Operative

  • Reconstruction with arthroscopic /open repair
    • for capsulolabral damage
    • rc tears
    • active young pts
31
Q

What are the complications of luxatio erecta?

A
  • Axillary n palsy
    • usually resolves with relocation of shoulder
  • Axillary artery thrombosis
    • may occur late
  • RC tear
    • older pts