Lecture 5 - Foot

Question 1

Explain what’s the ankle joint

Answer 1

Maintained by the talus between tibia and fibula.

Neutral position = strong bony anatomy stabilises joint (bony constraints suspectible for injury)
Plantar flexsion= soft tissues and ligs maintain stability (ligs suspectibel to injury)

Question 2

What are the most missable fractures around the ankle?

Answer 2

FLOAT

F - base of 5th metatarsal 
L - lateral malleoli 
O- os trigonum 
A- anterior calcaneus process 
T- talar dome

Question 3

Explain ankle sprains and their frequencies

Answer 3

77% of ankle injuries

Medial sprains = eversion (10-20% of sprains because it’s stronger ligament wise on this side)
Lateral sprains = inversion (common)

Ligaments around ankle from a solid ring that limit stretching capacity. If there is only a unimalleolar fracture present, there will be a ligament injury present at location around the ring

Question 4

Explain in more detail as to what are medial ankle sprains

Answer 4

An everison injury

Fracture of medial malleolus often occur BEFORE there is sprain of deltoid ligament

Sprain of deltoid lig causes an avulsion fracture of medial aspect of talus from the medial mallelous

Medial sprain can lead the medial mallelous fracture and damage sydesmotic complex (anterior tibiofibular ligament, intersosseous ligament)

High ankle sprain is a roatational pivoting injury and can cause syndemostic injury

Question 5

Explain with more detail as to what a lateral ankle sprain is

Answer 5

Inversion injury - with a degree of plantar flexsion

Impacts the anterior tibiofibular ligament with a tear or an avulsion fracture of commonly the fibula and less commonly the talar end of anterior talofibular ligament

Question 6

Explain the Ottawa Ankle rules

Answer 6

An ankle series should only be conducted when there is pain in the malleolar zone and

• bone tenderness in lateral mallelous region
• bone tenderness in medial mallelous region
• inability to weight bear

Question 7

Explain sites of ankle fractures in children

Answer 7

Epiphyseal fractures common, diaphysis (9-14 yo)

Distal metaphyseal or diaphyseal tibial fractures (toddlers fracture - child learning to walk)

Greenstick fracture of tibia and fibula very uncommon

Torus fractures can go undetected by a divergent beam (not cantered)

Question 8

Discuss ankle fractures in children

Answer 8

Ligaments a stronger in growing bones, so ligamentous injuries are rare in children

Physis is weakest point on bone and so leads to fractures with displacement

Soft tissue swelling, swollen capsule indicates a possible undisplaced or crush injury of the epiphysis

If AP AND LATERAL are negative and there’s strong fracture indication, Do an oblique

Question 9

Do all ankle fractures have a joint swelling?

Answer 9

Joints spaces are meant to be roughly the same size.

Question 10

What distinguishable about posterior ankle fractures?

Answer 10

There will be changes to the kager’s triangle.

When analysing ankle
- look for syndymostiv injury
- widening of space
-

Question 11

What forms the karges triangle?

Answer 11

Achilled tendon coming down, and the flexor tendons curving to form a triangle

Question 12

Explain the classifications of ankle joints in terms of Pott’s classifications

Answer 12

Classified in terms of the number of malleoli involved

So the injuries can be either unimalleolar, bimalleolar or trimalleolar

This classification system can’t distinguish between stable and unstable injuries

Unused now

Question 13

Explain the Danisweber classification of ankle fractures

Answer 13

Classifying according to the location of the distal fibular fragment relative to the syndesomsis

Type A (below)- fracture of lateral malleolus distal to syndemosis

• tibiofibular syndemosis intact
• deltoid ligament intact
• medial mallelous often fractured

Type B- fracture of fibula at level of syndemosis

• tibiofibular syndesmosis intact or partially torn, but no widening of distal tibiofibular articulation
• medial mallelous fractured or deltoid ligament torn

Type C(above)- fracture of fibula proximal to the syndesmosis

• tibiofibular syndesmosis disrupted with widening of distal tibiofibular articulation
• medial mallelous fracture or deltoid lig injury
• proximal fibula fracture near fibular neck (maissoneuve fracture)

Question 14

Why is the syndemosis so important?

Answer 14

You can have no fractures anywhere but this can be disrupted.
- ligamnetous intergy lost, and the interessojs membrane will tear

So a syndesmotic injury can have no bones fractures, and so the person goes undetected.

Question 15

Explain what a maissoneuve fracture?

Answer 15

type c criteria - hontelsu it’s just a frvature to the fibula with associative fractures to medial and posterior mallelous with lig damage

Tear of ATFL and interossesous membrane, separation of distal tibiofibular syndesmosis

Fracture of posterior mallelous or torn PTFL

Fracture of medial mallelous,most likely including deltoid lig

Spiral fracture of proximal fibula usually at neck, or midshaft

Fracture with displacement of proximal fibula or deltoid ligament

Posterior displacement of talusx

Question 16

Explain what a pylon fracture (Plafond)?

Answer 16

Due to high impact

Looks like maissoneuve fracture, as it has a fracture of posterior or medial mallelous

Multiple fractures (Comminuted) of plafond (articular surface on tibia)

Question 17

Name the fractures of the talar dome and explain what a talar dome fracture is

Answer 17

Occur due to compression and rotational forces

Lateral fractures commonly due to trauma but only 60% medial fractures due to trauma BUT medial talar fractures are more common than lateral talar fracture

Lesions not caused by trauma due to chronic overload and persistent microtrauma, AVN, CONGENITAL FACTORS

Delayed healing due to poor blood supply to talus and avascularity of articular cartilage

Talar dome lateral - inversion with Doris flexsion (tenderness ant. To lat. malleolus, along ant. Border)
Talar dome medial - inversion with plantarflexsion or atraumatic (tenderness post. To lat. mallelous, along posterior border of talus)

Question 18

Explain the stages of the talar dome fracture for medial and lateral dome

Answer 18

Stage 1 - translucent area due to repetitive microtrauma at medial or lateral

Stage 2 - a. Tiny fracture noticed with tiny fragment. B. Break in cortex noticed

Stage 3 - if break is big enough, the lateral projection will show fracture on the dome

Question 19

Name the fractures of the talar processes

Answer 19

Lateral talar process - rapid inversion with Doris flexsion (common is avulsion fracture, the process can be torn off if serious)

Posterior talar process - hyperplantar flexsion with forced inversion (similar to os trignonum)
- called posterior ankle impingement due to fracture of talar process or due to traumatic displacement of os trignonum

Question 20

What’s a peritalar disclocatiin

Answer 20

Talus just sitting there but everything has dislocated

Question 21

Explain what is anterior ankle impingement

Answer 21

Lateral ankle dorsiflexsion on a person with anterior ankle impingement will show

• anterior tibial spurring
• new bone formation on dorsal neck of talus due to stress on anterior attachment of capsule
• bony loose bodies anterior to tibia (joint mouse)

Question 22

What are transitional fractures

Answer 22

Inf infants the lower end of tibia starts to fuse in girls at 14 and 16 in boys

Fusion is about 18 months and is the transitional period and there are unique fractures associated with this stage
Epiphysis fusion: central-ant-post-medial-lateral

Eg. Triplane frvature is a transitional fracture
- extends away from physis in both directions (Into distal post portion tibia as well as into the joint), through epiphysis, physis, metaphysis

Eg. Juvenile tilleaux fracture= Salter Harris not reliable as it can appear type 3 and/or 2 on AP and type 2 on lateral
- widening of tibia fibula joint, malalignemnt