Foot & Ankle Anatomy - Clinical Correlation

Question 1

How many bones, joints, ligaments and muscles are there in the foot?

Answer 1

Bones: 28 + accessory

Joints: 33

Ligaments: 106

Muscles: 20

Question 2

What are common accessory bones?

Answer 2

• Os trigonum & accessory navicular are most troublesome
• Also os peroneum commonly

Question 3

What are the common tarsal coalitions?

Answer 3

• 45% talocalcaneal
• 45% calcaneonavicular
• 10% other

Question 4

What are the symptoms of tarsal coalitions?

Answer 4

Symptoms tend to occur in the same location, regardless of the location of coalition: on the lateral foot, just anterior and below the lateral malleolus. This area is called the sinus tarsi

The onset of symptoms related to a tarsal coalition usually occurs at about nine to seventeen years of age, with a peak incidence occurring at ten to fourteen years of age. Symptoms may start suddenly one day and persist, and can include pain (may be quite severe), lack of endurance for activity, fatigue, muscle spasms and cramps, an inability to rotate the foot, or antalgic gait.

Question 5

What are the two likely causations of ankle arthritis?

Answer 5

Commonly post-traumatic.

Consider haemochromatosis if no known trauma and under 50 years.

Question 6

Which starts earlier, hip or ankle arthritis?

Answer 6

Ankle - mean age of diagnosis of ankle arthritis is 46 years

Mean age of onset of hip arthritis is 51 years

Question 7

What are the sirgical procedures for ankle arthritis?

Answer 7

Plate and screws - fusing bones together

Ankle replacement

Ankle replacement is great if done well – but bad is done badly

• Fusion is preferential to bad ankle replacement

Question 8

What are the two tendons that form the achilles tendon?

Answer 8

• Formed by 2 tendons
• Gastrocnemius
• Soleus

Question 9

What are the tests possible for assessing if the an=chilles tendon is ruptured?

Answer 9

Simmonds triad of tests

Calf squeeze and no plantarflexion

Altered angle of dangle (the foot adopts a more dorsiflexed position)

Visible gap in the achilles tendon

Question 10

What does cavovarus foot look like?

Answer 10

The arch is very high and the heel slants inward. Both feet are often affected and the misalignment gradually worsens over time.

If caused by charcot-marie-tooth then it is bilateral

Question 11

What happens as a result of cavovarus foot deformity?

Answer 11

Pain, calluses, ankle sprains and stress fractures are all common results of cavovarus foot deformity.

Question 12

What might cavovarus foot indicate?

Answer 12

The condition may be a sign of a neurological disorder or Charcot-Marie Tooth disease, both of which can affect the nerves and weaken the muscles of the feet.

Question 13

What do the words cavus and varus mean?

Answer 13

Cavus means high arched

Varus means the heal has turned inward

Question 14

A feature of cavovarus foot is equinus, what does this mean?

Answer 14

Insufficicent ankle dorsiflexion for normal gait

Question 15

Here is the pathogenesis of deformity

Answer 15

• Weakness of intrinsic muscles - clawing of toes
• ‘Plunger-effect’ by proximal phalanges - plantarflexion of MT’s – also ‘overaction’ of peroneus longus
• Weakness of peroneus brevis - hindfoot varus
• Weakness of tibialis anterior - equinus
• Overpull of tibialis posterior - adduction of forefoot

Question 16

What are the clinical manifestations of the following deformities?

Clawing of toes and plantarflexion of metatarsals

Weakness of peroneus brevis

Weakness of tibialis anterior

Overpull of tibialis posterior

Answer 16

• Clawing of toes & plantarflexion of metatarsals - plantar callosities and shoe problems
• Weakness of peroneus brevis - hindfoot varus - ankle instability
• Weakness of tibialis anterior – equinus - altered gait
• Overpull of tibialis posterior - adduction of forefoot - stress fractures of lateral metatarsals

Question 17

What is the presentation of cavovarus foot?

Answer 17

Ankle sprains

Lateral foot pain (5th metatarsal stress fractures)

Plantar calluses on the 5th and the 1st metatarsal heads

Question 18

What is the physical test for cavovarus foot?

Answer 18

Coleman block test

Peek-a-boo heel

Question 19

What does the coleman block test assess?

Answer 19

place 1” block under the lateral foot

eliminates contribution of the plantarflexed 1st ray and forefoot pronation to the hindfoot deformity

findings:

flexible hindfoot will correct to neutral or valgus when block placed under lateral aspect of foot (if the hindfoot varus corrects, it shows hind foot flexibility)

rigid hindfoot will not correct to neutral

Differentiates between forefoot driven hindfoot varus and hindfoot driven varus.

https://www.youtube.com/watch?v=TCp25F0l7hc