Have you ever been working at 3am and wondered, “Am I missing something? I’ll just splint and instruct the patient to follow up with their PCP in 1 week.” This is a reasonable approach, especially if you’re concerned there could be a fracture. But we can do better. Enter the “Can’t Miss” series: a series organized by body part that will help identify injuries that ideally should not be missed. This list is not meant to be a comprehensive review of each body part, but rather to highlight and improve your sensitivity for these potentially catastrophic injuries. We’ve already covered the elbow and wrist. Now: the foot and ankle.
- 4% of all visits to the ED involve the ankle .
- The foot is a complex part of human anatomy and is a frequent cause for a visit to the Emergency Department .
- High morbidity if unstable injuries are missed.
Epidemiology/Importance: One of the most common tendon injuries of adults. Typically occurs after sudden plantarflexion or forced dorsiflexion of foot.
Symptoms: Sudden “pop” or as though they got “hit” in the back of the ankle. May have difficulty walking.
Physical Exam: Tenderness can be noted from calf down to the heel. There may be a palpable defect at the achilles. Make sure to check the Thompson Test. Note, this test may be falsely negative if a partial tear exists.
Diagnostic Imaging: Although not always present, look for pre-achilles fat pad (Kager’s fat pad) distortion on plain film (figure 1). Consider ultrasound to assess for partial versus full thickness tear.
Treatment: Non weight-bearing, Posterior splint in Equinus Position (20 degrees plantarflexion).
Check out CoreEM’s post on Achilles tendon rupture for more information.
Epidemiology/Importance: Suspect this injury with mechanisms including dorsiflexion and external rotation (eg. football, basketball, rugby, hockey, skiing, etc.) . This injury is much more likely to create long term instability .
Symptoms: Patient may have inability to walk or have anterior ankle pain.
Physical Exam: External rotation test: pain with slight dorsiflexion and external rotation. Positive tib/fib “Squeeze Test.” Talar Tilt Test: > 3 mm on Talar Tilt. Ability to hop on affected foot, lack of pain at syndesmosis, and negative external rotation tests are highly sensitive for ruling out syndesmosis injury .
Diagnostic Imaging: Look for > 5 mm increase in medial clear space or > 6 mm widening of tibiofibular space. Of note, plain films may only detect up 50% on AP and 66% on Mortise Views .
Treatment: Boot immobilization and non weight-bearing until follow up with orthopedics or sports medicine in 1 week.
Epidemiology/Importance: Most common isolated ankle fracture .
Symptoms: Tenderness to palpation at the lateral aspect of the ankle
Physical Exam: Most likely will be tender to palpation at lateral aspect. Make sure to check for signs of instability as above.
Diagnostic Imaging: Standard AP, Lateral, Mortise views will demonstrate fracture or unstable mortise. Consider stress view to assess for widening of tibiofibular space or medial space clearing.
- Weber A: Fracture below tibiotalar joint. Apply short leg walking boot and weight bearing as tolerated.
- Weber B or C: fracture at or above tibiotalar joint line. Apply short leg walking splint, non weight-bearing, and follow up in 1 week.
- Pearl: Management of Weber B fractures is institution dependent. Some institutions recommend a stress view. If normal, patients can be made weight-bearing as tolerated.
- Pearl: “Bi” or “Tri” fractures (ie. two or three malleoli fractures are identified) are always unstable. Place in a posterior leg splint with stirrup, non weight-bearing, and follow up with orthopedics. Consider ED consultation for any unstable ankle that is not amenable to splinting.
Epidemiology/Importance: Commonly missed associated fracture
Symptoms: Patient may not complain of fibular pain until palpation
Physical Exam: Tenderness to palpation anywhere along fibula
Diagnostic Imaging: Dedicated tibia/fibula x-ray will demonstrate fibular involvement
Treatment: Posterior long leg splint
- Pearl: If there is widening of the medial clear space on ankle x-ray but no other injury, strongly consider obtaining a tibia/fibula x-ray.
Epidemiology/importance: These injuries run a high risk of nonunion and avascular necrosis. Lateral process fractures have a high association with snowboarding . Talar neck fractures are often associated with axial loading.
Symptoms: Patients may report lateral ankle pain.
Physical Exam: Point tenderness over lateral process near anterior talofibular ligament.
Diagnostic Imaging: Best seen on ankle mortise view. Avulsion and comminuted fractures can also be seen on lateral .
Treatment: Posterior short leg splint, non weight bearing, close orthopedics follow up
Epidemiology/Importance: Most frequently fractured tarsal bone . Most common mechanism is fall from height. High risk to have concomitant spinal fractures.
Symptoms: Patient may have pain at heel.
Physical Exam: Palpate using heels of both hands and compressing rather than using a finger to press on certain areas.
Diagnostic Imaging: Perform Calcaneus films and measure Bohler’s Angle. If Bohler’s angle < 25 degrees, this is 100% sensitive for fracture . Consider a CT if there is a high index of suspicion regardless of x-ray results.
Treatment: Posterior splint, Non weight-bearing.
- Pearl: Up to 10% of calcaneus fractures can have associated compartment syndrome of foot.
Epidemiology/Importance: Typically caused by direct blow or axial loading . High risk of avascular necrosis .
Symptoms: Vague pain and swelling at midfoot.
Physical Exam: Tenderness and ecchymosis around navicular bone . May also see edema at midfoot near the navicular bone. Patients usually have full range of motion at ankle.
Diagnostic Imaging: AP, Lateral, and Oblique foot x-rays. Consider a CT if there is a high index of suspicion; plain films are only 33% sensitive for navicular fractures .
Treatment: Non weight-bearing, placement of posterior short leg or CAM boot and follow up with orthopedics.
Epidemiology/Importance: 20% are missed on initial ED presentation . Typically a high energy injury such as MVC. Typically occurs when an axial load is applied to a plantar flexed foot (ie. gas pedal in MVC).
Symptoms: Pain or swelling at midfoot. Patient typically has inability to bear weight .
Physical Exam: Pain with torsion of midfoot (aka midfoot stress test) [Wedmore]. Ecchymosis at base of foot, especially between 2nd and 3rd metatarsal.
Diagnostic Imaging: AP, lateral, oblique foot x-ray. The base of the metatarsals should line up with the cuboids/cuneiform.
- Pearl: Consider weight-bearing foot x-ray or CT if a strong index of suspicion remains after negative plain films.
- If < 1 mm displacement, place in posterior short leg splint, non weight-bearing, and follow up with orthopedics within 1 week.
- If displaced, the joint is unstable and needs reduction. There is high risk for compartment syndrome.
- Pearl: Make sure to feel for the DP pulse as this injury is high risk for vascular damage.
Check out CoreEM’s post on lisfranc injuries for more information.
Epidemiology/Importance: Commonly missed fracture. Further classification:
- Zone 1 (Pseudo-Jones or avulsion fracture): Proximal to 4-5th metatarsal articulation
- Zone 2 (Jones fracture): Involves 4-5th metatarsal articulation
- Zone 3 (Stress fracture) : Distal to 4-5th metatarsal articulation
- Pearl: Zone 2 and 3 fractures have high risk of malunion.
Symptoms: Pain with weight-bearing over lateral border of foot
Physical Exam: Tenderness at base of 5th metatarsal
Diagnostic X-Ray: AP, Lateral Oblique foot x-rays.
- Zone 1 or Pseudo-Jones can be placed in CAM boot or stiff shoe and weight bearing as tolerated.
- Zone 2 and 3 fractures should be non weight-bearing, placed in CAM boot or posterior short leg splint
Other radiology resources
First things first: always make sure to do a thorough ankle exam.
Check out Radiopaedia’s approach to the ankle x-ray.
Don’t Forget the Bubbles has a great post on their approach and pediatric considerations.
StartRadiology has a more comprehensive approach to the ankle.
- Handel et al. Chapter 273. Ankle Injuries. In: Tintinalli’s Emergency Medicine. A Comprehensive Guide, 8th edition. New York: McGraw-Hill Education, 2016.
- Wedmore, I. et al. Emergency Department evaluation and management of foot and ankle pain. Emerg Med Clin N Am 33. Issue 2. May 2015. PMID: 25892727
- Hunt et al. High Ankle Sprains and Syndesmotic Injuries in Athletes. J AM Acad Ortop Surg. Vol 23. No 11. November 2015. PMID: 26498585
- Kellet, J. et al. Diagnostic imaging of ankle syndesmosis injuries: A general review. J Med Imaging Radiat Oncol. Vol 62. No 2, April 2018. PMID: 29399975
- Aiyer, AA et al. Management of Isolated Lateral Malleolus Fractures. J Am Acad Orthop Surg. Vol 27. No 2, January 2019. PMID: 30278012
- Englanoff, G. et al. Lisfranc fracture-dislocation: A frequently missed diagnosis in the ED. Annals of Emergency Medicine. Volume 26, Issue 2. August 1995. PMID 7618790