Shoulder instability Flashcards
Traumatic anterior shoulder instability posterior instability & post dislocation mutlidriecitonal instability Luxatio erecta
What is the epidemiology of TUBS ( traumatic unilateral dislocation with a bankart lesion requiring surgery)?
- 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
What are the associated ligament injuries of TUBS?
- 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
-
Bankart lesion

Name the assoc fx with TUBS?
-
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

Name the assoc injuries of TUBS?
- Ligament/tendon injuries- rotator cuff tears
- Fractures
- nerve injury
Describe the nerve injury in TUBS?
- Axillary nerve
- most often a transient neurapraxia of the axillary nerve
- present in 5% patients
Describe the rotator cuff injuries in TUBS?
- 30% of TUBS patients >40 yrs
- 80% of TUBS pts >60 yrs
Describe the classification of TUBS?
- 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- grade 2- humeral head translation over rim with spontaneous reduction once force withdrawn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
What is the anterior shoulder static stability provided by?
-
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
What is the presentation of a pt with TUBS?
- 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
What is seen on imaging in a pt with TUBS?
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

What is the tx of TUBS?
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
Describe the epidemiology of posterior dislocation of shoulder?
- Less common
- often missed
- 2-5% unstable shoulders
- risk factors
-
bony abnormality
- glenoid retroversion/hypoplasia
- ligamentous laxity
-
bony abnormality
- Mechanism
- trauma 50%
- microtrauma
- seizure/electric shock
What are the associated conditions of a posterior shoulder dislocation?
- 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
what are the primary stabilsers in a posterior shoulder?
-
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
What is the presentation of posterior dislocation of shoulder?
- 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
- posterior load and shift test

What is seen on imaging of posterior dislocation of shoulder?
- 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

What is the tx of posterior dislocation of shoulder?
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

What are the complicaitons of posterior shoulder dislocations?
- Recurrence 7-50%
- Adhesive capsulitis
- Generalised stiffness
-
overtightening of posterior capsule
- -> anterior subluxation
- Nerve injury
- axillary/ suprascapular
Describe multidirectional shoulder instability?
- 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
What is seen on pathoanatomy of multidirectional shoulder instability?
- 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
What is the presentation of multidirectional shoulder instability?
- 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

What is seen on imaging of multidirectional shoulder instability?
- 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
What is the tx of multidirectional shoulder instability?
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
Can you describe the technical aspect of capsular shift/stabilisation procedure ( open or arthroscopic)?
- 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
What are the complications of multidirectional shoulder instability surgery?
-
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
What is luxatio erecta?
- 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

Describe the static glenohumeral restraints?
- 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
How does someone present with luxatio erecta?
- Shoulder pain
- inabilty to move shoulder
- neurovascular injury
O/E
- Presents with arm overhead with shoulder in full abduction and elbow flexion

What is seen in imaging of luxatio erecta?
- Xray
- inferior glenohumeral dislocation w arm fully abducted
- MRI
- post shoulder relocation to assess shoulder injuries
- may have capsulolabral pathology
- rotator cuff tears common

What is the tx of luxatio erecta?
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

What are the complications of luxatio erecta?
-
Axillary n palsy
- usually resolves with relocation of shoulder
-
Axillary artery thrombosis
- may occur late
-
RC tear
- older pts