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- grade 2- humeral head translation over rim with spontaneous reduction once force withdrawn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