Loco orthopaedics

Question 1

Most common fracture

Answer 1

<75 = Colles 
>74 = hip

Question 2

Comminuted fracture

Answer 2

2 or more bone pieces

Question 3

Places where avulsion fractures can occur

Answer 3

Ischial tuberosity = hamstring
Medial epicondyle = flexors and pronators
ASIS = sartorius
AIIS = rectus femoris

Question 4

Where are bust fractures most common?

Answer 4

Thoraco-lumbar junction

Question 5

Types of stress fracture

Answer 5

Fatigue = abnormal stress on normal bone 
Insufficiency = normal stress on abnormal bone

Question 6

Stage 1 of bone healing

Answer 6

Fracture haematoma
Blood clot forms
low pH and hypoxia
Recruitment of inflammatory cells

Question 7

Stage 2 of bone healing

Answer 7

Soft callus 
New capillaries remodel haematoma 
Inflammatory cells remove dead bone 
Fibroblasts and chondrocytes begin to produce fibrous tissue = soft callus 
Osteoblasts begin to enter area

Question 8

Stage 3 of bone healing

Answer 8

Hard callus

Osteoblasts produce woven bone to replace soft callus

Question 9

Stage 4 of bone healing

Answer 9

Remodelling

Woven bone is remodelled into lamellar bone

Question 10

Blood loss from fractures

Answer 10

Tib/fib = 500ml 
Femur = 500ml 
Pelvic = 2000ml

Question 11

Nerve injuries as a result of trauma

Answer 11

Neurapraxia = nerve compression without axonal disruption 
Axonotmesis = axoplasmic disruption but endoneurial sheath intact 
Neurotmesis = axon and axon sheath disrupted

Question 12

Absolute indications for ORIF

Answer 12

Displaced intra-articular fractures 
Open fractures 
Fractures with vascular injury or compartment syndrome 
Pathological fractures 
Non-union

Question 13

Relative indications for ORIF

Answer 13

Loss of position with closed reduction
Poor functional result
Displaced fracture with poor blood supply

Question 14

Radiological union

Answer 14

When 3 out of 4 cortices are healed

Question 15

Signs of fat embolus

Answer 15

Hypoxaemia
Petechial rash
Neurological signs –> snowstorm appearance on MRI

Question 16

Compartment syndrome pressures

Answer 16

Normal = 0-10mmHg
Capillary blood flow compromised = >20mmHg
Nerve and muscle fibre damage = >30-40mmHg

Question 17

Hybrid and reverse hybrid hip replacement

Answer 17

Hybrid = cemented stem and cement less cup

Reverse hybrid = cementless stem and cemented cup

Question 18

Characteristics of body part used for tendon transfer

Answer 18

Under voluntary control
Expendable
Adequate tendon length
Be innervated to a different nerve to the one that was damaged

Question 19

When is tendon transfer done?

Answer 19

Nerve palsy

Question 20

What muscle imbalances occur in cerebral palsy?

Answer 20

Quadriceps > hamstrings

Plantarflexors > dorsiflexors

Question 21

What can be used for ACL reconstruction?

Answer 21

Patella-ligament-tibia 
Hamsting tendon (semitendinosis, gracilis)

Question 22

Define delayed healing

Answer 22

Failure in 1.5x normal time

Question 23

Define non-union

Answer 23

Failure in 2x normal time

Question 24

Sites of autograft harvesting

Answer 24

Iliac crests
Ribs
Fibula
Mandible

Question 25

Properties of bone grafts

Answer 25

``` Osteoconduction = scaffold for cells Osteoinduction = molecules in graft induce neighbouring cells to become osteoblasts Osteopromotion = graft material enhances osteoinduction (but does not induce osteoblast differentiation itself) Osteogenesis = cells in the graft are capable of producing bone ```

Question 26

What pathologies can cause toe walking?

Answer 26

Cerebral palsy Duchenne muscular dystrophy Nervous system problems

Question 27

Risk factors for talipes equinovarus

Answer 27

Breech presentation CT disorders Poly/oligohydramnios Family history

Question 28

Treatment of talipes equnovarus

Answer 28

Ponseti method

Question 29

Risk factors for CHD

Answer 29

Breech delivery | First born child

Question 30

Presentation of CHD

Answer 30

Asymmetrical leg length Uneven thigh and gluteal folds Leg turned into external rotation Limited abduction

Question 31

Diagnosis of CHD

Answer 31

``` Barlow = adduction Ortolani = abduction Galeazzi = leg length ```

Question 32

What should normal alpha angle be on ultrasound

Answer 32

>60

Question 33

Hilgenreiner's line

Answer 33

Between inferior aspects of triradiate cartilages

Question 34

Acetabular angle

Answer 34

<30 degrees | Gets smaller with age

Question 35

CHD treatment

Answer 35

Pavlik harness Hip spica Closed reduction Corrective osteotomy

Question 36

Stages of Perthes disease

Answer 36

Necrosis Fragmentation Re-ossification Remodelling

Question 37

SUFE presentation

Answer 37

Limited internal rotation

Question 38

Risk factors for SUFE

Answer 38

Obesity Hypothyroidism Early or late puberty

Question 39

Klein's line

Answer 39

Along superior border of femoral neck | Should intersect femoral head

Question 40

Blount's disease

Answer 40

Medial tibia growth problem | Leads to varus deformity

Question 41

Kohler's disease

Answer 41

Osteochondrosis disorder affecting the foot joints