OSCEs Crash Course

Question 1

Orthopaedic Emergencies

Answer 1

1) Compartment syndrome
2) Necrotising fasciitis
3) Open fracture
4) Cauda Equina Syndrome

Question 2

Things to mention on Xray

Answer 2

1) Patient biodata - skeletally mature?
2) What view - request orthogonal view, Is it weight bearing
3) What limb - is the no. of joints sufficient?
4) Fracture where - exact part, intra/extra-articular
5) Fracture pattern - transverse, spiral, oblique, comminuted
6) Displacement - translated, angulated, rotated, shortened, distracted (lengthened)
7) Special names (eponyms) + classifications

Question 3

What is AMPLE history?

Answer 3

Allergies
Medications
Past medial history
Last meal
Events leading to presentation

Used for trauma Hx taking

Question 4

Definition of open fracture

Answer 4

Fracture that communicates with external environment

Question 5

Classification of open fracture? Used when?

Answer 5

Gustilo-Andersen

Used only AFTER debridement

Question 6

5 Ps of compartment syndrome

Answer 6

Pain (out of proportion), pallor, paresthesia, paralysis, pulselessness

Pulselessness can be last to present because it takes a lot of pressure to occlude an artery

Question 7

How to check compartment syndrome in unconscious patient?

Answer 7

Stryker needle

Delta pressure = diastolic - compartment pressure

Delta pressure <30mmHg = compartment syndrome

Question 8

What is the result of severe muscle ischemia after compartment syndrome?

Answer 8

Volkmann’s ischemic contracture

Question 9

Management of compartment syndrome

Answer 9

1) Escalate to senior
2) Remove all compressive dressings
3) Analgesia according to WHO
4) Pre-op prep
5) Emergency FASCIOTOMY

Question 10

Difference between fasciotomy & fasciectomy

Answer 10

otomy - cut open, for compartment syndrome

ectomy - remove fascia, for nec fasc

Question 11

Pre-op prep

Answer 11

Pre-op bloods: GXM, FBC , Renal panel, coagulation panel

Pre-op labs: ECG, CXR

Keep pt NBM

Question 12

Hallmark features of nec fasc

Answer 12

Swollen, erythematous
Ecchymoses
Haemorrhagic bullae
Pain out of proportion
Pt in sepsis

Question 13

Investigations for nec fasc

Answer 13

Clinical management - should NOT wait for MRI to confirm diagnosis then start treatment

Lab: pre-op bloods + ESR/CRP + lactate + BLOOD CULTURE

Radio: Xray for subcutaneous emphysema, Urgent MRI to see fluid tracking fascia planes

Question 14

Management of nec fasc

Answer 14

1) Fluid resus if pt in septic shock
2) IV broad spectrum antibiotics
3) Escalate to senior

Definitive mgmt
1) Emergency fasciectomy/amputation
2) Debridement of nonviable tissue

Question 15

Causes of cauda equina syndrome

Answer 15

Compression of cauda equina (L2 and below) - acute loss of lumbar plexus function

COMMON: central PID
others: abscess, tumour, haematoma, trauma, late stage spondylolisthesis

Question 16

Presentation of cauda equina syndrome

Answer 16

Saddle anaesthesia
Bowel/bladder dysfunction (urinary retention)
Lower limb weakness (both legs)
Radiating pain (both legs)

Question 17

Knee OA xray features

Answer 17

WEIGHT BEARING XRAY

loose bodies
loss of joint space - usually medial first
osteophytes
subchondral sclerosis
subchondral cysts (never see dont say)

REQUEST LONG LIMB FILM
- see genu varum

Question 18

What classification for OA knee

Answer 18

Kellgren-Lawrence

Question 18

OA symptoms

Answer 18

Mechanical pain
- worse on movement
- morning stiffness <30mins

Walk how long; climb stairs?

Associated: numbness, weakness, stiffness, systemic involvement?

Question 18

Mgmt OA

Answer 18

Conservative: PT, weight loss, activity modification, analgesia, H&L (triamcinolone and lignocaine in SG)

Surgical: HTO, unicompartment arthroplasty, TKR

Question 19

RA Xray features

Answer 19

Symmetrical loss of joint space (panarthritis)

Can develop secondary OA

Question 20

RA symptoms

Answer 20

Inflammatory pain - relieved by activity, morning stiffness >1hr

Other signs:
- swelling >3 joints
- RA nodules
- Arthritis of MCP, PIP, wrist

Question 21

Investigations for RA

Answer 21

Anti-CCP (cyclic citrullinated peptide)

Question 22

ACL tear history

Answer 22

Injury mechanism - twisting, pop sound
Immediate swelling
Can weightbear? TRO fracture
Instability
Locking? TRO meniscus tear

Question 23

PE for ACL

Answer 23

Swelling
Lachman’s +ve, ant drawer +ve
Valgus stress test -ve (TRO unhappy triad)

Question 24

Ix for ACL

Answer 24

Xray - segon fracture (avulsion of lateral edge of tibia due to ACL tear)

MRI - ACL tear

Question 25

Mgmt ACL

Answer 25

Conservative: physio, bracing, activity modification, analgesia

Surgical: ACL reconstruction

Question 26

Blood supply to head of femur

Answer 26

femoral artery -> profunda femoris -> Medial & lateral circumflex femoral artery -> retinacular arteries

Question 27

Classification of neck of femur fractures

Answer 27

Intracapsular (use Garden’s) - subcapital, transcervical

Extracapsular - basicervical, intertrochanteric

Question 28

Why is intracapsular NOF # prone to AVN and less likely to heal?

Answer 28

retinacular arteries disrupted

Intracapsular bathed in synovial fluid - washes away clotting factors to form callus and heal

Question 29

NOF # patients present with ___ and ___ femur, disrupted ___

Answer 29

shortened, externally rotated (lesser trochanter seen more obviously)

Shenton’s line

Question 30

Garden’s classification

Answer 30

NOF # (intracapsular)

Stage I: incomplete
Stage II: complete, undisplaced
Stage III: complete, partially displaced
Stage IV: complete, completely displaced

Question 31

Physical exam for NOF #

Answer 31

Pt presents leg abducted, externally rotated, shortened

NV status: sciatic nerve most commonly injured

Question 32

Surgical options for NOF #

Answer 32

1) Head preserving - Garden I and II, young pt (fixation w screw)

2) Replacing - hemiarthroplasty (less fit pts), THR (fit pts)

Question 33

Complications of THR

Answer 33

1. GA risks - stroke, MI, death
2. Surgical risks - sciatic nerve damage (foot drop), infection, bleeding, implant loosening, femur fractures