Mandible x-rays

Cite this article as:
Tessa Davis. Mandible x-rays, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.10597

An orthopantomogram (OPG) is a good view to demonstrate most mandibular fractures.

 

A PA mandible shows the displacement of fractures. It also demonstrates symphysis menti fractures which can be missed on the OPG.

pa-anatomy

Image from WikiRadiography

If an OPG cannot be obtained, a lateral view can be helpful. The body and ramus can be viewed along with the TMJ articulation.

lateral-anatomy

Image from WikiRadiography

 

Know your anatomy

mandible-anatomy

Image from WikiRadiography

 

 

Follow the line of the mandible.

  • Remember that the air-filled oesophagus often means that black lines cross the mandible near the angle of the mandible (see image above).

 

Look at the condylar and coronoid process, rami and body, submental symphysis, and alveolar ridge for fractures

  • Condylar process fractures can occur at the base so look carefully as they are easily missed.
  • In general, if you see one mandibular fracture then look for another one as it is common to have more than one, or TMJ dislocation.

 

A Guardsman’s fracture is where there is a fracture of the symphysis and both condyles. This is due to a fall with impact on the midpoint of the chin.


Management

  • Favourable fractures are held in alignment.
  • Unfavourable fracture are displaced by the muscles pulling them.
  • Mandibular fractures of the body or angle of the mandible can be managed conservatively, unless they are displaced, in which case reduction and internal fixation may be required.
  • Condylar fractures are usually managed conservatively, unless there is occlusion of normal movement due to dislocation of the condylar head.

If you want to test yourself then Norwich Image Interpretation Course has a great online facial x-ray quiz.

Can you see what I see?

Cite this article as:
Andrew Tagg. Can you see what I see?, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.10302

When it comes to imaging children we are all about the ALARA (as low as reasonably achievable) approach. One of the best ways to do this is not to use radiation at all. Unfortunately not all of us can be Casey Parker, and so we might need some help with our ultrasound skills.

Ankle x-rays

Cite this article as:
Tessa Davis. Ankle x-rays, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.9992

The ankle joint consists of three bones – the tibia, the fibula, and the talus.

The ankle also consists of two joints – the ankle joint (where the tibia, fibula and talus meet) and the syndesmosis joint (the joint between the tibia and fibula which is held together by ligaments).

There are three main sets of ligaments:

  • Medial: deltoid ligament
  • Lateral: posterior talofibular, anterior talofibular and calcaneofibular ligaments
  • Syndesmotic ligament

Ankle views

An x-ray of the ankle will have three views – AP, mortise, and lateral. It should be noted though, that in some countries, including the UK, only the mortise and lateral are used. See the annotated images below from WikiFoundry, and thanks also to Radiopaedia:

In the AP view:

  • The distal fibula should be slightly superimposed on the tibia
  • The lateral and medial malleoli should be in profile
  • The tibiotalar space should be open (although the full mortise isn’t visible)

In the mortise view:

  • This aims to assess the articulation of the ankle joint
  • The lateral and medial malleoli should be in profile
  • The mortise should be uniformly visible
  • The base of the fifth metatarsal should be included in the view

In the lateral view

  • The following bones can be assessed: tibia, fibula, talus, cuboid, navicular, calcaneus, and fifth metatarsal
  • The distal fibula should be superimposed by the posterior part of the distal tibia
  • The talar domes should be superimposed
  • The joint space between the tibia and the talus should be uniform

N.B. Assess each bone individually, and if you see a break in one, then look for a second break.

1. Trace around the tibia and fibula in both views.

Be mindful that an ankle fracture can be unstable and therefore it’s important not to miss them.

2. Pay particular attention to the fibula on the lateral view for an oblique fracture.

Oblique fracture (from Radiology Key)

3. Look at the mortise and the talar dome.

Make sure the space is uniform, and that the talar dome surface is smooth.

Osteochondral fracture (from Radiopaedia)

4. Look at the interosseous ligament.

Measure the gap between the tibia and the fibula 1cm proximal to the tibial plafond. It should be less than 6mm, otherwise, consider a ligament rupture which could be associated with a fracture.

Image result for interosseous ligament rupture xray
Widened gap between tibia and fibula

5. On the lateral view trace the lateral and medial malleolus, the posterior tibia, the calcaneus, and the base of the 5th metatarsal.

6. Assess the Bohler’s angle

  • Draw two lines at tangents to the anterior and posterior aspects of the calcaneus
  • The angle should be 20-40°
  • If it’s less than 20° then consider a calcaneus fracture
Calcaneus fracture (from Radiopaedia)

7. Do a final check around the bones to make sure you haven’t missed anything the first time around.

8. Remember about accessory ossicles – they aren’t fractures!

  • There are three common accessory ossicles in the ankle: os trigunum (usually forms at 7-13 years old); os subtibiale (when the medial malleolus epiphysis fails to fuse with the tibia in the later teenage years); os subfibulare (can also be an unfused ossification centre or an avulsion fracture).

Common fractures and their management

The level of the fracture directs the treatment – fractures can be classified according to the Salter-Harris classification.

Salter-Harris classification of fractures

Lateral malleolus fracture

In children, a fibula fracture usually requires a short leg cast and six weeks of non-weight bearing. Salter-Harris I distal fibula fractures can be diagnosed if there is tenderness directly on the lateral malleolus (rather than the ligaments) and many recommend treating it as a fracture even if no radiographic fracture is noted.

However, a study in JAMA carried out MRI scans on 135 children with presumed SH1 distal fibula fractures. All children were treated with a removable leg brace and advised to continue regular activities as tolerated. 4 of the children had an SH1 on MRI, 38 had an avulsion fracture, and the rest showed ligamentous injury or bony contusion. By 1 month, 72.1% had full weight-bearing activity and by 3 months 96.9% had returned to normal activities (it didn’t matter which type of injury they had on MRI). Therefore, a removable brace may be appropriate for a Salter-Harris I, if your department stocks them. (See a full summary of this article on ALiEM).

Medial malleolus fracture

An undisplaced distal tibia (Salter-Harris I or II) can be managed with a long leg cast and non-weight bearing. SH3 or 4 needs discussion with ortho. All will have a fracture clinic follow up in a week or so.

Salter-Harris I distal tibia fractures can be diagnosed if there is tenderness directly on the medial malleolus (rather than the ligaments) and many recommend treating it as a fracture even if no radiographic fracture is noted.

The most common distal tibial epiphysis injury is a Salter-Harris II

The high occurrence of Salter-Harris III and IV fractures is because the lateral and deltoid ligaments insert here and they are stronger than the physis itself.

A Tillaux fracture is a Salter-Harris III but with avulsion of the anterolateral corner of the distal tibial epiphysis. If there is <2mm displacement then the patient can have a long leg cast, and be non-weight bearing, with ortho discussion and follow-up. If there is >2mm displacement then an ortho review will be required as typically this need operative management.

Pilon fracture

A pilon fracture is where there is an axial load on the tibia and the talus is pushed into the tibia plafond.

If the fracture is non-displaced or very distal, it is unlikely to require surgery. It would usually be treated with a short leg cast, and weight-bearing would be avoided for six weeks.

If it is displaced or the ankle is unstable, then surgery may be required to avoid non-union, so speak to the ortho team.

Posterior malleolus fracture

Posterior malleolus fracture (from Wikiradiography)

Usually, when this has happened, there is also a lateral malleolus fracture (because they share ligament attachments). The ankle can be unstable if a large piece is broken and therefore surgery may be indicated – so speak to the ortho team.

An untreated posterior malleolus fracture can lead to arthritis because of the disruption to the cartilage surface.

If the fracture is not displaced then it would usually be treated with a short leg cast, and weight-bearing would be avoided for six weeks.

Talar neck fracture

Talar neck fracture

This fracture carries a high risk of avascular necrosis.

If the fracture is non-displaced then it can be managed with a short leg cast or a boot. If it is displaced then surgery will be required.

Bimalleolar fracture

Bimalleolar fracture (from Radiopaedia)

If two parts of the malleoli are broken then the ankle is not stable and surgery is usually needed.

Trimalleolar fracture

Trimalleolar fracture (from Radiopaedia)

If all three malleoli are broken then there can be associated dislocation. The ankle will be unstable and will require ortho input.

Maisonneuve fracture

This fracture is uncommon in children but can occur. It is where there is a spiral fracture of the proximal fibula along with ankle instability. On x-ray, there can be syndesmotic widening.

mason1
From Wheeles Online

In adults, this can be managed with a long leg cast, but in children, it will require operative fixation.

Syndesmotic injury

Overlap between the tibia and fibula in a syndestomic injury (thanks to Bone School)

The joint between the tibia and fibula are held together by ligaments. If this ligament is sprained then this is a syndesmotic injury.

As mentioned above, there can be a widening of the clear space between the medial border of the fibula and the lateral border of the posterior tibia (>5mm). You can also get an overlap of the fibula and the anterior tibial tubercle (>6mm on the AP views, >1mm on the mort

When do I need an orthopaedic review immediately?

  • Open fracture
  • Salter-Harris III or IV
  • Neurovascular injury
  • Compartment syndrome
  • Unable to reduce the fracture

Ref: RCH

Should we be worried about growth plates?

Growth arrest doesn’t occur immediately after the injury, and can even occur in seemingly benign fractures. It can be delayed for up to 6 months and so it is important to follow up ankle fractures post-injury.

Selected References

Wheeless Online

Radiopaedia

Royal Children’s Hospital, Melbourne

Radiology Masterclass

(Ed: Thanks to Eyston Vaughan-Huxley for his input too).

Through the looking glass

Cite this article as:
Andrew Tagg. Through the looking glass, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.9685

As we head out winter in the southern hemisphere the northern hemisphere can see that ‘Winter is Coming’ and with it the scourge of the paediatric emergency departments – bronchiolitis.  It’s one of those diseases that the we should all be able to spot but the real challenge is picking up those that present as if they have bronchiolitis but in fact have a different disease entity altogether. 

Sedation for transport

Cite this article as:
Andrew Tagg. Sedation for transport, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.8397

One of your colleagues, Andy, has been lucky enough to grab a ticket to a prestigious international conference to be held in Dublin. He is thinking about taking his children but wonders how to keep them happy on the long international flight. He wonders if you have any tricks up your sleeve for keeping children calm during transit.

DFTB in EMA #5 – Sticks and stones may break some bones

Cite this article as:
Andrew Tagg. DFTB in EMA #5 – Sticks and stones may break some bones, Don't Forget the Bubbles, 2016. Available at:
https://doi.org/10.31440/DFTB.8055

This month in the EMA the DFTB team look at how we might treat a simple forearm fracture.

“Up to a quarter of the paediatric population of the UK present to an ED annually with a large number being due to falls. High-risk activities such as scooter riding, climbing on monkey bars and backyard trampolines are partially to blame although the implementation of safety netting for trampolines has led to a reduction in injuries.”

You can read the article here.

Reference:

Tagg, A., Goldstein, H., Davis, T., and Lawton, B. (2016) Sticks and stones may break some bones.Emergency Medicine Australasia, doi: 10.1111/1742-6723.12531.

Knee X-rays

Cite this article as:
Tessa Davis. Knee X-rays, Don't Forget the Bubbles, 2014. Available at:
https://doi.org/10.31440/DFTB.6471

1.  Know your knee anatomy

See the the anatomical landmarks on the diagrams below.

landmarks2

From wikiradiography.net

From https://www.wikiradiography.net/

From wikiradiography.net

 

Remember that the knees of younger children will look different, as the patella forms, and the ossification centres form.

childknee

From thesebonesofmine.wordpress.com

 

2. Look for an effusion

There are two fat pads in the knee

  • the suprapatellar fat pad
  • the prefemoral fat pad

Make sure they are next to each other. Soft tissue density in between the two fat pads indicates an effusion – this is only reliably seen on the lateral view (see images below).

It is sometimes helpful to rotate the PACS view so you are looking at the knee in the horizontal plane, in the same way the image is taken.  Your eyes are much more adept at picking up an effusion or even a fat/fluid level (lipohaemarthrosis) that way.

fatpads

Case courtesy of Dr Jeremy Jones, Radiopaedia.org, rID: 29039

kneeeffusion2

Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID: 32559

3. Look at the main bones

Check for fractures in the fibular head, femur and tibia.

 

4. Check the tibio-femoral alignment

Draw a line along the margin of  the lateral femoral condyle. The tibia should be within 0.5 cm of this line, otherwise it suggests a tibial plateau fracture.

tibiofemoral alignment

Case courtesy of Dr Jeremy Jones, Radiopaedia.org, rID: 29039

 

5. Looks at the tibial plateaus

These most commonly happen on the lateral tibial plateau.

tibialplateau

Check for a tibial plateau avulsion from the lateral edge (Segond fracture)

segond

From orthopaedicsone.com

Tibial plateau fractures in children are exceedingly rare and require a marked degree of axial force. They are more likely to get a Salter-Harris V.

6. Look at the intercondylar eminence

A fracture here is most common in adolescents following hyperextension of the knee. It’s an avulsion fracture at the tibial attachment of the ACL.

tibial eminence

Case courtesy of Gerry Gardner, Radiopaedia.org, rID: 13915

 

 

7. Look for patellar tendon disruption

The patellar tendon goes from the inferior pole of the patella to the tibial tuberosity. Its length should be the same as the patellar length +/- 20%. If it’s too long then think of a patellar tendon rupture. This is the Insall-Salvatti ratio and should ideally me measure with the knee flexed at 30 degrees.

insall-salvatti

Case courtesy of Dr Wael Nemattalla, Radiopaedia.org, rID: 10329

 

8. Look for a patellar fracture

Bipartite patellas are common. It is a congenital condition that occurs when the patella is made of two bones instead of a single bone. Normally the two bones would fuse together as the child grows but in bipartite patella they remain as two separate bones. The edges appear well corticated as compared to in a fracture. See an example below.

bipartate

Case courtesy of Radiopaedia.org, rID: 11236

Most patella fractures are transverse, but they can be vertical.

Patella_fracture

 

Consider a skyline view. This gives a clearer view of the patella in cases of clinically suspected patella fracture where the AP and laterals look ok. It gives a good view of the space between the patella and the femur. See a normal skyline view below.

skyline

From wikiradiography.com

 

9. Remember the fabella…

This is a normal variant and not a floating fracture! It’s normal sesamoid bone that lies in the posterior knee.

fabella

Case courtesy of Dr David Cuete, Radiopaedia.org, rID: 27428

 

References

Interpreting x-rays of the knee join – YouTube video

Knee radiograph: an approach. Radiopaedia

Trauma x-ray, Radiology Masterclass

SonoKids Pneumonia

Cite this article as:
Tessa Davis. SonoKids Pneumonia, Don't Forget the Bubbles, 2014. Available at:
https://doi.org/10.31440/DFTB.6310

This week’s vodcast is a great new series by SonoKids. Kasia Hampton gives us a crash course in diagnosing pneumonia using ultrasonography. In this vodcast that is less than ten minutes long, Kasia covers all the basics. It starts with an overview of the normal lung anatomy as seen on ultrasound and continues right through to the signs to look for in pneumonia. By the end, you feel ready to get started and try it yourself.

We look forward to hearing more from SonoKids.

[niceyoutubelite id=”h8XrY_8cBHA”]

 

What could cause bright red blood vomits in a neonate?

Cite this article as:
Yamamoto, L. What could cause bright red blood vomits in a neonate?, Don't Forget the Bubbles, 2014. Available at:
https://dontforgetthebubbles.com/bright-red-blood-neonate/

A 6-day old infant male vomits a large amount of bright red blood at home and is taken to a rural emergency department. The child looks good, but the amount of blood on the baby’s blanket brought in by his mother is very impressive.