Common dislocations

Question 1

What are the two most common dislocations?

Answer 1

Shoulder

Knee - patella

Question 2

What might you expect to see on inspection of a dislocation?

Answer 2

Deformity

Question 3

What should you palpate for before any intervention on a dislocation?

Answer 3

Blood and nerve supply

Question 4

By which mechanisms do shoulder dislocations most commonly occur?

Answer 4

Fall
Traction
Seizure

Question 5

In which directions can a shoulder dislocate?

Answer 5

Anterior
Posterior
Luxatio erecta (i.e inferior)

Question 6

Who most commonly presents with a shoulder dislocation?

Answer 6

Young adults

Elderly with weakened soft tissues

Question 7

What is the most common direction for a shoulder to dislocate?

Answer 7

Anterior

Question 8

By which mechanism does an anterior shoulder dislocation occur?

Answer 8

Fall backwards (shoulder externally rotated)

Question 9

How must an anterior shoulder dislocation be assessed?

Answer 9

Badge area sensory assessment to rule out compression of the axillary nerve

Question 10

By which mechanisms does a posterior shoulder dislocation occur?

Answer 10

Fall (shoulder internally rotated)

Direct blow to anterior shoulder

Question 11

How does a patient with an inferior shoulder dislocation hold their arm?

Answer 11

In abduction

Question 12

How must an inferior shoulder dislocation be assessed?

Answer 12

Prompt neurovascular assessment and reduction

Question 13

What is the radiological sign indicating a posterior shoulder dislocation?

Answer 13

Light bulb sign

Question 14

How is a shoulder dislocation managed?

Answer 14

Closed reduction under anaesthetic
Stabilisation
Rehabilitation

Question 15

When might a shoulder dislocation be managed with an open reduction?

Answer 15

Fixed posterior dislocations

Question 16

What is the main predictor of recurrent instability with a shoulder dislocation?

Answer 16

Age - the older the patient is the less likely it is to recur

Question 17

What are the three main techniques of shoulder reduction?

Answer 17

Hippocratic, kocher’s, in line traction

Question 18

By which mechanism does an elbow dislocation occur?

Answer 18

Fall onto outstretched hand

Question 19

Who gets elbow dislocations?

Answer 19

Adults

Children

Question 20

In which directions can an elbow dislocate?

Answer 20

Anterior
Posterior
Medial
Lateral

Question 21

What are the associated risks with an elbow dislocation?

Answer 21

Radial head fracture

Coronoid process fracture

Question 22

By which mechanism does a radial head dislocation commonly occur?

Answer 22

Traction (pulling on the forearm)

Question 23

Who gets radial head dislocation?

Answer 23

Children and infants

Question 24

What is the risk for recurrent instability with an elbow dislocation?

Answer 24

Low

Question 25

How is elbow dislocation managed?

Answer 25

Closed reduction under anaesthetic 2 weeks in a sling Extensive rehabilitation

Question 26

Why do elbow dislocations need to undergo rehabilitation?

Answer 26

They are prone to stiffness

Question 27

How is an elbow dislocation reduced?

Answer 27

Traction in extension +/- pressure over olecranon

Question 28

By which mechanisms do interphalangeal joint dislocations occur?

Answer 28

Hyperextension | Direct axial blow

Question 29

In which direction does interphalangeal joint dislocation most commonly occur?

Answer 29

Posterior

Question 30

What are the associated injuries of a dislocated interphalageal joint?

Answer 30

Phalangeal herniation through volar plate | Associated fracture --> recurrent instability

Question 31

How are interphalangeal joint dislocations managed?

Answer 31

Closed reduction with digital/metacarpal block | 2 weeks in neighbour strapping

Question 32

How is an interphalangeal joint dislocation managed if it's unstabled?

Answer 32

Volar slab in edinburgh position

Question 33

How are interphalangeal joint dislocations reduced?

Answer 33

In line traction with corrective pressure

Question 34

What is the mechanism of patellar dislocation?

Answer 34

Sudden quadriceps contraction while the knee is bent

Question 35

What is the direction of patellar dislocation?

Answer 35

Lateral

Question 36

Who gets patellar dislocation?

Answer 36

Teenagers (girls)

Question 37

What are the associations with patellar dislocation?

Answer 37

``` Hypermobility Hypoplastic lateral femoral condyle Increased Q-angle (genu valgum, femoral neck anteversion) Lateral quads insertion Weak vastus medialis ```

Question 38

What is typically found on examination on patellar dislocation?

Answer 38

Medial pain Patellar apprehension test positive Effusion

Question 39

What is the cause of the effusion in patellar dislocation?

Answer 39

Haemarthrosis

Question 40

What is the cause of medial pain in patellar dislocation?

Answer 40

Torn medial retinaculum

Question 41

How patellar dislocation managed?

Answer 41

``` Reduction on extension Radiograph Aspirate Brace Physiotherapy ```

Question 42

How is repeat patellar dislocation managed?

Answer 42

Surgically - lateral release + medial reefing OR patellar tendon realignment

Question 43

Are knee dislocations high or low velocity?

Answer 43

Most often high velocity

Question 44

Can knee dislocations spontaneously relocate?

Answer 44

Yes

Question 45

Which injuries indicated a knee dislocation that has spontaneously relocated?

Answer 45

Lateral collateral ligament injury | Peroneal nerve injury

Question 46

Who typically gets knee dislocations?

Answer 46

Teenagers with ligamentous laxity (girls)

Question 47

What directions can the knee dislocate?

Answer 47

``` Medial Lateral Rotatory Posterior Anterior ```

Question 48

What is the most common direction the knee dislocates?

Answer 48

Posterior

Question 49

What are the common vascular injuries caused by a knee dislocation?

Answer 49

Popliteal artery Vein injury Intimal tear/thrombus

Question 50

What nerve gets injured with a knee dislocation?

Answer 50

Peroneal injury

Question 51

How is a knee dislocation monitored for complications?

Answer 51

Normal exam - monitor | Clinical concern - arteriogram or MRI

Question 52

How is ligamentous injury checked with knee dislocation?

Answer 52

Examination under anaesthetic

Question 53

How is a knee dislocation managed?

Answer 53

Reduction under anaesthetic | Stabilise in splint/external fixation

Question 54

When might surgical reduction be required for knee dislocation?

Answer 54

Condyle herniation through capsule

Question 55

What type of imaging is indicated for knee dislocations and why?

Answer 55

X-rays for associated fractures | MRI

Question 56

What type of early surgery is indicated for knee dislocations?

Answer 56

Vascular repair | Nerve repair

Question 57

What type of definitive surgery is indicated for knee dislocations?

Answer 57

Sequential ligamentous repair

Question 58

What are the possible complications of knee dislocation?

Answer 58

Post-traumatic arthritis and stiffness Nerve/artery injury Ligamentous laxity

Question 59

What is the common mechanisms of hip dislocation?

Answer 59

RTA - dashboard injury Fall from height (High velocity)

Question 60

What is the most common direction of hip dislocation?

Answer 60

Posterior

Question 61

What are the fractures associated with hip dislocation?

Answer 61

Posterior acetabular wall | Femoral

Question 62

How does a dislocated hip present?

Answer 62

Flexed Internally rotated Adducted knee

Question 63

How is a hip dislocation managed?

Answer 63

``` Neurovascular assessment X-ray Urgent reduction Possible stabilisation in-traction Imaging/CT ```

Question 64

What nerve is at risk in hip dislocation?

Answer 64

Sciatic

Question 65

What are the complications of hip dislocation?

Answer 65

Sciatic nerve palsy Avascular necrosis Secondary osteoarthritis of the hip Myositis ossificans