Episode 172.0 – Ankle Sprains

We dissect one of the most common injuries we see in the ER -- ankle sprains

Hosts:

Brian Gilberti, MD

Audrey Bree Tse, MD

https://media.blubrry.com/coreem/content.blubrry.com/coreem/Ankle_Sprains.mp3



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Tags: Orthopedics

Show Notes

Background

Among most common injuries evaluated in ED
A sprain is an injury to 1 or more ligaments about the ankle joint
Highest rate among teenagers and young adults

Higher incidence among women than men

Almost a half are sustained during sports
Greatest risk factor is a history of prior ankle sprain

Anatomy

Bone: Distal tibia and fibula over the talus → constitutes the ankle mortise
Aside from malleoli, ligament complexes hold joint together

Medial deltoid ligament
Lateral ligament complex

Anterior talofibular ligament

Most commonly injured
Weakest
85% of all ankle sprains 

Posterior talofibular ligament
Calcaneofibular ligament

Syndesmosis

Mechanism of Injury

We dissect one of the most common injuries we see in the ER -- ankle sprains

Hosts:

Brian Gilberti, MD

Audrey Bree Tse, MD

https://media.blubrry.com/coreem/content.blubrry.com/coreem/Ankle_Sprains.mp3



Download


3 Comments





Tags: Orthopedics

Show Notes

Background

Among most common injuries evaluated in ED
A sprain is an injury to 1 or more ligaments about the ankle joint
Highest rate among teenagers and young adults

Higher incidence among women than men

Almost a half are sustained during sports
Greatest risk factor is a history of prior ankle sprain

Anatomy

Bone: Distal tibia and fibula over the talus → constitutes the ankle mortise
Aside from malleoli, ligament complexes hold joint together

Medial deltoid ligament
Lateral ligament complex

Anterior talofibular ligament

Most commonly injured
Weakest
85% of all ankle sprains 

Posterior talofibular ligament
Calcaneofibular ligament

Syndesmosis

Mechanism of Injury

Lateral ankle sprains 

Most common among athletes
ATFL most commonly injured

Combined with CFL in 20% of injuries

2/2 inversion injuries

Medial ankle sprains

Less common than lateral because ligaments stronger and mechanism less frequent

More likely to suffer avulsion fracture of medial malleolus than injure medial ligament

2/2 eversion +/- forced external rotation
Typically landing on pronated foot -> external rotation

High Ankle sprains

Syndesmotic injury
More common in collision sports (football, soccer, etc)

Grade I

Mild
Stretch without “macroscopic” tearing
Minimal swelling / tenderness
No instability
No disability associated with injury

    Grade II

Moderate
Partial tear of ligament
Moderate swelling / tenderness
Some instability and loss of ROM
Difficulty ambulating / bearing weight

    Grade III

Severe
Complete rupture of ligaments
Extensive swelling / ecchymosis / tenderness
Mechanical instability on exam
Inability to bear weight

Examination

    Beyond visual inspection for swelling, ecchymoses, abrasions, or lacerations

Palpation 
Pain when palpating ligament is poorly specific but may indicate injury to structure
Check sites for Ottawa ankle rules to evaluate if there may be an associated fracture with injury

Posterior edge or tip of lateral malleolus (6 cm)
Posterior edger or tip of medial malleolus (6 cm)
Base of fifth metatarsal
Navicular bone

Acute ATFL rupture / Grade III Sprain

90% chance of this injury if hematoma and localized tenderness with palpation present on exam over this ligament 
Anterior drawer test

Assess for anterior subluxation of talus from the tibia

Ankle in relaxed position, distal extremity is stabilized with one hand while the other cups the heel to apply anterior force

Compare to contralateral side
Difficult to determine if there is an acute rupture at this point and may be more easily diagnosed in subacute phase (4-5 days after injury)
Ability to perform exam adequately limited by pain, swelling and potential muscle spasm

Talar tilt test

If applying inversion force to ankle and there is excessive mobility → calcaneofibular ligament

Thompson test

Can be performed if there is concern for concomitant Achilles tendon injury 

Do not miss a Maisonneuve fracture by palpating proximally about the fibular ahead as forces may be transmitted through the syndesmosis 

Squeeze test – pressure just proximal to ankle

If elicits pain → concern for syndesmotic injury

Diagnostics

    X-rays indicated if unable to rule out using Ottawa Ankle Rules

Sn (Up to 99.6) (one of the best validated tools we use in the ER)
May have trouble applying rule if there is question of patients ability to sense pain (diabetic neuropathy), in which case obtain radiographs

Treatments

    RICE

Crutch train so they can be weight bearing a tolerated
Ideally initiate within first 24 hours of injury
Ice 15-20 minutes q2-3h over the first 48 hours or until swelling improves

    NSAIDs

Topical and PO are better than placebo 
We do not know if PO is superior to topical NSAIDs

    Early mobilization / Functional Rehab (sample patient instructions here)

Work to restore range of motion, strength, proprioception
For Grade I and II, can begin as soon as the patient can tolerate and ideally within 1 week of the injury
Patients return to work sooner, decreased chronic instability, less recurrent injuries
Dorsiflexion, plantarflexion, and perform foot circles as well as toe curls, inversion and eversion as tolerated
Proprioception

Balancing on wobble board

Continue exercises until patient is able to return to activities at full capacity, without pain

Immobilization

High re-injury rates and important to protect against this
Grade I

No immobilization required
+/- Ace wrap

Grade II

Aircast brace
Ensure patient understands that they should still partake in rehabilitation exercises

Grade III

Data conflicts
RCT, multicenter study comparing aircast brace, compression bandage, Bledsoe immobilization boot and below-knee cast for 10 days

Ankle function at 3 months

Cast group had most improvement
No difference at 9 months in function or complications

May be institution-dependent and a cast can be offered initially

Prognosis

Acute inflammation → reduction in swelling → development of new tissue → strengthening of tissue 
Return of basic function, though limited, occurs over 4-6 weeks depending on severity of sprain
Try to limit strain put on joint (no heavy lifting, walking on uneven surfaces, try to limit standing while at work)
Follow up:

If pain or instability does not improve over 4-6 weeks
Grade III sprains
Medial ankle sprains (may have underlying fracture that was undetected in ED on XR)
Syndesmosis injuries (protracted recovery course)
Injuries associated with fractures or dislocation / subluxation

 

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