Triplane ankle fractures

Cite this article as:
Anna O'Leary. Triplane ankle fractures, Don't Forget the Bubbles, 2020. Available at:
https://doi.org/10.31440/DFTB.23578

Sean is 13 years old. He was playing basketball but when he jumped to score a basket he landed awkwardly on his ankle, twisting and externally rotating it. He immediately fell to the floor on the court and couldn’t weight bear on it. The swelling and bruising increased and he attended his local emergency department where he was told that he had a triplane ankle fracture.

 

Epidemiology

Although triplane ankle fractures account for only 5-15% of overall paediatric ankle fractures, along with Tillaux fractures, they are the most common ankle fractures in adolescents. This type of fracture represents a unique spectrum of injury that does not fit neatly into the Salter-Harris classification of physeal injury. They occur before complete closure of the distal tibial physis (hence why they occur in adolescents whose epiphyseal plates are closing) and are classically seen in 10-17 year olds. They are slightly more common in males.

 

History

Adolescents with triplane fractures will usually present to the emergency department with a very painful and swollen ankle after a twisting force to the leg during athletic or recreational activities. They are usually very reluctant or unable to weightbear.

 

Examination

There will often be swelling and bruising with focal or referred pain at the affected ankle. There may be deformity of the ankle. It is important also to examine skin integrity and the presence of neurologic defects or vascular injuries. Don’t forget to palpate the full length of the fibula to evaluate for a proximal fracture as well as along the foot to evaluate for injuries such as a fracture to the base of the 5th metatarsal.

 

Investigations

AP and lateral ankle xrays will help evaluated the fracture type. Addition of a mortise view, performed with the leg internally rotated approximately 15 degrees to allow better assessment of the articular space, should be included to assess the amount of displacement if this can’t be fully appreciated on the AP view (although in some countries the AP view is a mortise view).

The triplane fracture on x-ray looks like a Salter-Harris II or III depending on whether this is a medial or lateral triplane fracture. The fracture is in all three planes, classically looking like a Mercedes sign on CT.

 

Triplane Mercedes sign. From Orthobullets

 

It may be classified as in 2, 3 or 4 parts.

 

It is important not to miss fibular fractures which are seen in 50% of triplane fractures. Typically this is a spiral fracture pattern located proximal to the physis in children nearing skeletal maturity.

CT scans are not routinely performed in the emergency department but may be organized by the orthopaedic team. Small dislocations and the vertical component of the fracture are not infrequently overlooked. CT is therefore often organized to fully delineate fracture pattern and to assess the degree of intra-articular congruity.

 

Management

In the ED, as with any injury, ensure you prescribe adequate analgesia and provide assistance with non-weight bearing status, such as a wheelchair or crutches depending on the ability of the child. Placement in a boot or cast for comfort prior to definitive treatment by the orthopaedic team is appropriate.

Once the diagnosis is made, ongoing care depends on the degree of displacement. Orthopaedic review for consideration of conservative management versus operative management is important as these fractures will often need CT imaging to ensure adequate delineation of fracture pattern.

 

Conservative management

Fractures with minimal displacement (<2mm), particularly if they are 2 part triplane fractures, can often be managed with closed reduction and casting. If the fracture is in 3 or 4 parts, closed reduction is difficult to achieve.

Post reduction, place in a long leg/above knee cast for 3-4 weeks to control the rotational component of the injury, followed by a further 2-4 weeks in a short leg cast or walking boot to initiate ankle range of movement.

 

Operative Management

Any triplane fracture with >2mm displacement or that is in 3 or 4 parts is likely to require ORIF (Open Reduction, Internal Fixation). Intra-articular reduction to within 2 mm is required for optimal treatment of these unique paediatric ankle fractures.

A CT showing triplane fracture requiring ORIF with >2mm of displacement. You can clearly see why the fracture is called triplane, as it extends in 3 planes: coronal, sagittal and axial. Image from Orthobullets

 

Complications and Risks

  • Growth Arrest:

The main concern in an adolescent with a triplane fracture is growth arrest. This occurs in between 7-21% of triplane injuries. This is often insignificant but does mean that patients with more than 2 years of growth remaining must be closely followed up.

  • Ankle Pain and Degeneration:

Rare but increased risk with articular step greater than >2mm.

 

Controversies

As with all things orthopaedic, the debate continues: should these fractures be managed operatively or conservatively? Though still in preliminary research stages, recent evidence suggests that non-operative treatment of triplane fractures may have comparable clinical and radiographic results to operative treatment. Discussion with the orthopaedic team is advised prior to discharge given the different management options.

 

Things not to miss!

Don’t forget to examine the rest of the child’s lower limb when they present with a painful swollen ankle as there may be an associated accompanying fracture. Ensure that you examine and especially palpate both the foot and the entire length of the fibula. With rotational forces, proximal spiral fibula fractures and base of 5th metatarsal fractures are relatively common with triplane fractures. Carefully check and document neurovascular status as nerve injury can occasionally be associated with spiral fibular fractures.

Triple fracture with accompanying spiral fibula fracture. From Orthobullets

 

Sean was found to have a 2 part nondisplaced Triplane Fracture and was placed in an above-knee cast and followed up at his local orthopaedic outpatient clinic. He had interval x-rays which showed good healing and no evidence of displacement. After 4 weeks he was switched to a walking boot to encourage early ankle mobilization for another 2 weeks. He is looking forward to next year’s basketball season already!

 

References

Schnetzler, Kent A et al 2008 ‘The Pediatric Triplane Ankle Fracture’ The Journal of the American Academy of Orthopaedic Surgeons 15(12):738-47

Hyman et al, MSK Key https://musculoskeletalkey.com/transitional-ankle-fractures-juvenile-tillaux-and-triplane-fractures/ Accessed at 09/02/20

Beaty JH, Kasser JR. Rockwood and Wilkins’ Fractures in Children. 6th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006:1105

https://orthoinfo.aaos.org/en/diseases–conditions/ankle-fractures-in-children/

Min Ryu, Seung et al 2017 ‘Is an operation always needed for pediatric triplane fractures?’ Journal of Pediatric Orthopaedics B 27(5):1 · November 2017

https://www.orthobullets.com/pediatrics/4029/triplane-fractures

https://orthoinfo.aaos.org/en/diseases–conditions/ankle-fractures-in-children/

Ankle sprains

Cite this article as:
Neil Thomspon. Ankle sprains, Don't Forget the Bubbles, 2020. Available at:
https://doi.org/10.31440/DFTB.22248

David, 11, intends to play football in the Premier League when he is older.  Before then, he must serve his time with the school team.  During training, he ships a heavy tackle and rolls over his ankle. He limps over to the sideline and calls for help. Taking no risks with his future star, the coach insists mum takes him to ED. You are waiting with your game face on.

Having seen one or two sore ankles before, you are aware of the Ottawa ankle rules, but what are they? And are they applicable in kids?

 

Ottawa ankle rules

The Ottawa ankle rules are an evidence-based decision tool to advise indication for x-ray in an ankle injury.

An ankle x-ray series is required if:

There is any pain in the malleolar zones and…

  • bony tenderness over the posterior aspect of distal 6cm of tibia (i.e. medial malleolus)

OR

  • bony tenderness over the posterior aspect of distal 6cm of fibula (i.e lateral malleolus)

OR

  • inability to weight bear (>4 steps) both immediately after the injury and in the ED

 

A foot x-ray series is required if:

There is any pain in the midfoot zone and…

  • bone tenderness at the base of the 5th metatarsal

OR

  • bone tenderness at the navicular

OR

  • inability to weight bear (>4 steps) both immediately after the injury and in the ED

 

Practice common sense – these rules are not applicable if your patient is: unable to give a reliable answer; has other distracting injuries; has diminished sensation in legs; is too swollen to establish bony tenderness; unable to walk prior to the injury.  Remember that a patient who walks with a limp is able to weight bear.

The rules were designed with adults in mind, however, they have been shown to be reliable in the assessment on children. They are sensitive but not specific for detecting fractures, therefore, they are most useful in ruling out fractures (and the need for imaging).  For every 1000 patients that exhibit negative Ottawa ankle rules, 14 will actually have fractures.

 

David does not meet the criteria for imaging.  He does have a swollen ankle with tenderness over the anterior aspect of his lateral malleolus.  You suspect an ankle sprain.

 

What is an ankle sprain?

A sprain occurs when you stretch or tear a ligament.

Symptoms include pain, swelling, bruising, tenderness, impaired function and joint instability (if severe).

Classification of a sprain:

  • Grade 1 is stretching of the ligament, minimal swelling or bruising, no joint instability
  • Grade 2 is a partial rupture of the ligament, moderate swelling or bruising, no joint instability
  • Grade 3 is total rupture of the ligament, severe swelling or bruising, with joint instability

There are three main sets of ligaments in the ankle

  • Lateral – Anterior Talo-Fibular Ligament (ATFL), Calcaneo-Fibular Ligament (CFL), Posterior Talo-Fibular Ligament (PTFL)
  • Medial – Deltoid ligament
  • Interosseous (tibiofibular) ligament

There are two tests for instability, which should be compared between the good and bad ankles:

  1. Anterior drawer test – stabilize the leg with one hand, use the other hand to cup the heel and draw the foot anteriorly. If there is excessive movement then the test is positive.
  2. Talar tilt test – stabilize the leg with one hand, use the other hand to cup the heel and rock the foot in an inversion movement. If there is excessive movement then the test is positive.

 

How should I manage an ankle sprain?

A simple PRICE approach, along with analgesia, is the first line of management:

Protection. For example, with a supportive boot.

Rest. Usually for 72 hours.

Ice. Cover ice in a tea-towel and apply to the ankle for 10-15minutes every 2-3 hours.

Compression. An elasticated bandage will help with swelling and provide some support (but should be removed at night).

Elevation. Elevate the ankle until the swelling goes down.

Early mobilization as tolerated will facilitate faster recovery, however more severe sprains may require a period of immobilization. (7-10 days).

Supervised physiotherapy has been shown to benefit in early follow-up but does not make a difference in the long term.

What is the prognosis?

The recovery period depends on the severity of the sprain. A grade 1 sprain may return to play in 1-2 weeks; whilst a more severe sprain may return to walking in 1-2 weeks, running in 6-8 weeks and return to regular sporting activity in 8-12 weeks.

 

David’s ankle was strapped up in a Tubigrip and he limped home, eager to get back on the pitch and continue his journey to stardom.

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).