Lateral Ankle Sprains: Mechanisms, Grades, and Interventions

What is the primary mechanism of injury for a lateral ankle sprain?

Often occurs with a plantarflexed ankle moving into inversion.

What muscle may contract to limit inversion during a lateral ankle sprain?

The fibularis muscles.

What can occur if the ankle overcorrects into eversion after a sprain?

A deltoid sprain.

What type of lesions can accompany a lateral ankle sprain?

Osteochondral lesions, especially on the talus.

What is mechanical instability in the context of ankle injuries?

Described in terms of anatomic laxity.

What is functional instability regarding the ankle?

A person's perception of the ankle giving way, often referred to as chronic ankle sprain.

What are common causes of functional instability in the ankle?

Lack of neuromuscular control and proprioception.

What percentage of post-sprain patients experience functional instability?

40%.

What is the #1 risk factor for lateral ankle sprains?

Prior sprains.

How does limited ankle dorsiflexion range affect ankle stability?

It puts the ankle closer to an open packed position, making it more vulnerable.

What are the characteristics of a Grade I ankle sprain?

Tenderness of the ATF, pain with inversion, anterior drawer test pain but no laxity, little swelling, and minor loss of motion.

What distinguishes a Grade II ankle sprain from a Grade I?

Involvement of the ATF and possible fibularis involvement, with more ecchymosis, swelling, and functional deficits.

What are the signs of a Grade III ankle sprain?

Involvement of the ATF and CFL, significant swelling and ecchymosis, and positive anterior drawer and talar tilt tests.

What special test assesses the integrity of the calcaneofibular ligament?

Medial Talar Tilt Test.

What is the purpose of the Anterior Drawer test?

To test for ATF integrity.

What are some common differential diagnoses for lateral ankle sprains?

Fractures, other sprains, fibularis strain, lateral ankle impingement, cuboid syndrome, and osteochondral lesions.

What are the initial interventions for managing a lateral ankle sprain?

Edema management (ICE, compression, elevation) and early weight-bearing with assistive devices.

What is the recommended recovery time for a Grade III ankle sprain?

31-55 days.

What is the role of bracing in ankle sprain prevention?

Bracing prevents inversion but not combined movements of inversion, plantarflexion, and internal rotation.

What is the expected timeline for returning to sports after an ankle sprain?

Light plyometrics at 8-12 weeks, straight running at 12 weeks, and cutting at 16 weeks.

What percentage of athletes can return to high-level sports post-surgery for ankle injuries?

94%.

What are the specific precautions after surgery for ankle injuries?

Partial weight-bearing for 2 weeks in a CAM boot, then weight-bearing as tolerated with a brace for 4-8 weeks.

Patients start light plyo for

8-12 wk

Straight running at ______ and cutting at ________

12 wk, 16 wk

Specific precautions after surgery like ______________________ then ____________________, then _______________after surgery, ______________________

PWB 2 wk CAM boot

WBAT brace for 4-8 wk

Ankle AROM 2-4 wk

INV PF beyond 30 deg limited in first 6 wk