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Trauma Skeletal Radiology

A Practical Guide

Foot

L J Brimicombe

Clinical Specialist

Skeletal Radiology

FOOT

Systematic Film Evaluation

Alignment

Bones

Cartilage

Soft Tissue

Evaluate the ABC’S!

Alignment

Bowing

Normal position

of bones

Spaces between

bones

Symmetry

Angulations

Bones

Anomalies in the cortex, breaks, overlaps &

steps.

Changes in trabecular pattern

Changes in densities

Periosteal Reaction

Cartilage

Look for avulsion

fractures

Misalignment

Effusions

Soft Tissue

1. Defect on normal contours

2. Obvious swelling

3. Foreign body (e.g. glass) in

soft tissues

4. A fluid/solid interface

5. A gas/fluid interface

FOOT FOREFOOT

– Metatarsals' + Phalanges

MIDFOOT – Navicular, Cuboid +

– Lat, Middle & Medial Cuneforms

HINDFOOT – Talus + Calcaneum

Foot Anatomy

Foot Anatomy

Foot Anatomy

Ossification Centres

Calcaneus, talus - at birth

Cuboid - after birth

Lat Cuneform - about 1 yr

Med Cuneform - about 2yrs

Middle Cuneform - about 3yrs

Navicular - 5yrs

Epiphysis at the base and head of the phalanx centres appear about 4yrs and fuse at 18yrs

Dislocation of phalanx

Metatarsal Fracture

5th Apophysis & Fracture

March/Stress Fracture

Peroneus Brevis

Avulsion fractures are

common at the tuberosity

at the base of 5th

metatarsal.

This is at the insertion of

the peroneus brevis

tendon

Avulsions occur due to

inversion injuries

Jones Fracture >1.5 cm distal to 5th MT tuberosity

•Poorer prognosis than avulsion fractures

•Requires non-weight bearing treatment

Children's 1st metatarsal injury

LisFranc Fracture Dislocation

Lisfranc injury is a fracture at the base of the 2nd metatarsal with subluxation laterally from the tarso-metatarsal joint

Most common foot dislocation

20% missed on initial plain films

Trauma but also associated with charcot

Normal Foot Alignment

AP OBLIQUE OBLIQUE

Lisfranc Fracture Dislocation

Cuneform Fractures – wedge shaped

Cuboid Fracture

Avulsion Fracture Nutcracker Fracture

Navicular Fracture

Navicular

Latin for boat shape

Scaphoid like bone

Avulsions of Navicular & Talus

Avulsion fractures of the dorsal surface of the navicular and head of talus are common and often missed. These can only be identified by a lateral view:

Talus Aviators Astragalus

Talus – Latin Astragalus – Greek

1919 Anderson, consulting surgeon to the Royal Flying

Corps in WW1 described 18 cases of fracture and

dislocation of the talus. The association of injuries of

the talus with aircraft crash was so strong that he

named them “Aviator’s Astragalus.”

Fractures include compression fractures of the talar

neck, fractures of the body, fractures of the posterior

process, or fracture dislocation injuries

Talus - Aviators Astragalus

Talar neck is the most frequently injured site

The talus is the second most injured bone in the foot

Talus - Aviators Astragalus

Avascular necrosis

is a potential

complication of

neck fractures

Talus Posterior Pole # - Snowboarders!

Subtalar Dislocation Basketball Disloc.

Calcaneum – Most common fractured tarsal

Calcaneum – compression

Bohler’s Angle not within

normal limits

Calcaneum – Anterior Process

Bifurcate ligament:

Connects the anterior process of the

calcaneus to both the cuboid and

navicular

Inversion stress of the foot will result

in stretch of this ligament or avulsion

fracture of the anterior process

Calcaneum Avulsion

A 2nd common site is seen

lateral to the calcaneum

Only seen on a foot x-ray

At the insertion of the extensor

digitorum brevis muscle

Accessory Ossicles Posterior

1= Os cuneometatarsale I plantare

2= os uncinatum

3= os sesamoideum tibialis posterior

4= os sesamoideum peroneum

5=os cuboideum secundarium

6=os trochleare calcanei

7=os in sinus tarsi

8=os sustentaculum tali

9=os talocalcaneale posterius

10=os aponeurosis plantaris

11=os subcalcaneum

More Accessory Ossicles - Anterior

12=os sesamoideum tibialis anterior

13=os cuneometatarsale tibiale

14=os intermetatarsale

15=os cuneometatarsale dorsale

16=os paracuneiforme 17=os cuneonaviculare

18=os intercuneiforme 19=os intermetatarsale

20=os talonaviculare 21=os vesalianum pedis

22=os tibiale externum 23=os talotibiale dorsale

24=os supratalare

25=os calcaneus secundarius

26=os subtibiale 27=os subfibulare

28=os retinaculi

29=os calcaneus accessorius

30=os trigonum 31=os supracalcaneum

32=os tendinis calcanei

Most Common Accessory Ossicles

Usually originate from

secondary centres of

ossification that do not

unite with the main

centres

Differentiated from

fractures:

- bilateral presentation

- smooth rounded well

and corticated border

Os Naviculare

Os Tibiale Externum

Os Peroneum

Os Trigonum

Osteochondritis Dissecans

Seen in young athletic people in trauma

• Subchondral bone below the articular

cartilage loses its blood supply

• The bone and its overlying cartilage

become damaged, a fragment of bone

may separate to form loose bodies in

the joint

• The process occurs particularly in the

femoral condyles of the knee, and also

in the talus and hip joints

Charcot Neuro-osteoarthropathy

A degenerative disease with progressive

destruction of the bones and joints.

It is seen in patients with neurological disorders

with sensory loss of the feet, including tabes

dorsalis, leprosy, diabetic neuropathy, and

other conditions involving injury to the spinal

cord.

Charcot Foot

In the early stages radiographic abnormalities

are not present.

The acute stage of Charcot neuro-

osteoarthropathy shows rapid and progressive

bone and joint destruction within days or

weeks.

Immobility by total contact casting can prevent

further bone and joint destruction.

On the right an image of a patient with diabetic

neuropathy and a red hot foot. Normal x-rays

may not exclude the diagnosis of acute

Charcot neuro-osteoarthropathy.

Within 4 months there is progressive decrease

of calcaneal inclination with equinus deformity

at the ankle. Destruction of the tarsometatarsal

joint is seen, with the typical rocker-bottom

deformity.

Charcot Foot

Progressive neuro-

osteoarthropathy of

the tarsometatarsal

joints.

Lisfranc dislocation

subchondral cysts

erosions,

.

Pitfalls - Foot

Over penetration for toes

Cutting the soft tissue off

X-raying the whole foot when a toe is specified

Over turning oblique's so the metatarsals

overlay each other

Questions?