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 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   Read More