The ankle joint was one of the last things I studied in anatomy waaaay back in university; probably in First or Second Med. It seemed to be a victim of priority and as a result was never studied that well. Yet we see 'sprained' ankles all the time in the ED and there is a goodly proportion of them that end up in the circuit medical centre. 

Often it's an official who has rolled their ankle while accessing or leaving their track position. Sometimes someone has gone over in the paddock. It might also be an injury to a mechanic who gets pinned between heavy pieces of equipment or a competitor who jars their ankle in the footwell of the car during a heavy impact. Medics who have covered historic race categories will know that while the professional series have evolved, cars in which the driver's feet project beyond the front wheel axis are still in play.

Anyone who has heard John Hinds' presentation on Cases From The Races will be aware of the prevalence of ankle injuries in motorbike racers. Weird stuff happens with bike racers and a friend who runs a motor sport medical response agency at a circuit near me once showed me a photo of a rider who was run over by his own bike and ended up with his leg trapped in the rear wheel arch between the rear wheel and the rear portion of the chassis, with associated fractures.

A severe ankle injury may redirect or end a professional competitor's career.
A missed ankle injury may condemn anyone to crippling osteoarthritis in later life.

So it's useful to refresh the approach to examining an ankle and revising the key injuries to be aware of and their initial management.

A/Prof Anton Helman

Anton Helman is a Canadian emergency physician and associate professor who practices in Toronto. He is a significant FOAMed contributor and co-founder of the practical and informative Emergency Medicine Cases site and podcast. It is a good site to dip in and out of.

Earlier in the year I plugged into Episode 105 to listen to while walking to work. It is such a good refresher and there is often a wide skill mix amongst the doctors, paramedics and nurses that support motorsport events that I am putting it up on the Rollcage Medic site.

The EM Cases post and podcast

Commonly Missed Ankle Injuries - 
Emergency Medicine Cases Episode 105, hosted by Canadian ED physician A/Prof Anton Helman.

Episode 105 pearls

- Read the accompanying text. It helps to build a pattern of post-injury ankle assessment and has helped me to streamline how I approach ankle injuries (see below).

- It's helpful to consider the ankle structure as a ring composed of three bones
  • tibia & medial malleolus, 
  • fibula & lateral malleolus, 
  • the calcaneus 
and three ligaments
  • syndesmosis, 
  • medial & deltoid ligaments, 
  • lateral ligaments) 
all of which surround the talus (the donut hole). Ankle joint instability requires a disruption at 2 or more points in the circle, or an isolated lateral malleolar fracture, or an isolated syndesmotic disruption.

{Reproduced with permission from Emergency Medicine Cases Episode 105}.

- Consider an external rotation mechanism as the “thunderclap headache” or “chest pain radiating to the back” of the ankle.

- Complete inability to weight bear is a red flag for serious injury

- The Ottowa Ankle Rules

Ottowa Ankle Rules on MD Calc
  • These are often incompletely applied; ie. we usually remember to check that the person can weight bear, but forget to specifically examine the distal 6cm of the posterior margins of the tibia and fibula. 
  • There is more to ankle injury assessment than just the Ottowa Ankle Rules

- The ankle exam starts at the knee - See the examination approach detailed below

- Palpating the anterior margin of the ankle joint is really important and lessens the risk of missing an important talar dome, Tillaux fracture or syndesmosis injury

- Refusal to weight bear, with anterior ankle pain, and a mechanism of external rotation with ankle dorsiflexion should be considered to have a syndesmosis injury until proven otherwise. The recovery time is 4 - 6 months!!

- Watch out for the Tillaux fracture in junior competitors - Again, refusal to weight bear, with anterior ankle pain, and a mechanism of external rotation with ankle dorsiflexion in an 10 - 15 year old and it can occur with a low energy mechanism. It is essentially a distal tibial Salter-Harris III fracture.

- Treat the talus bone like the ankle's scaphoid - Always feel along its margins. If in doubt, get imaging as a missed talar fracture can have devastating mobility consequences later in life.

- An axial load to the foot that results in external rotation and dorsiflexion and associated with lateral ankle pain is a trigger to look for a talar lateral process fracture. Although often referred to as the snowboarder's fracture, the mechanism can be produced when a competitor's foot is axially loaded as the person braces their feet in the footwell or slips off a brake or clutch pedal during a hard impact.

My approach to an injured ankle

- Is this the first injury to that ankle ever? -> Sets a precedent and a comparison context

- Is there a history of diabetes or alcoholism or any other condition that might result in altered distal limb sensation that may mask injury. Patients with osteoporosis have a lower fracture threshold and absence of pain may be an unreliable indicator.

- Did the person walk or limp in? We're they carried? -> Weight bearing capacity. Syndesmosis injuries will tip toe limp if they can weight bear at all.

- Is there visible swelling or bruising?

- Start far away with a mid calf squeeze (Hopkin's test) -> Syndesmotic injury, Maisonneuve and Dupytren's fractures

- Palpate all margins of the ankle joint, keeping in mind the Closed Ring Model, and include the distal 6cm of the posterior margin of the distal tibia and fibula (Ottowa Ankle rule) and the anterior margin of the ankle joint (syndesmotic injury, Tillaux fracture, talar fracture), as well as the lateral and medial ankle ligament insertion points.

- Examine for pain on passive dorsiflexion and external rotation -> Syndesmotic injury, talar fracture

Ankle examination flow

Though it's uncommon to be able to obtain x-rays at many motor sport events, this EM Cases post has a series of great tips on interpreting ankle x-rays which are particularly handy if your day job does not involve this skill on a regular basis. They also go through which injuries require non-weight-bearing cast immobilisation and what kind of follow up should be arranged.

As an added bonus, once you have read the text and listened to the podcast, to consolidate the learning Anton has tacked on a series of Test Your Knowledge questions.

Oh, and don't forget the analgesia.