Ankle sprain

Background

stress tests-best done several days after injury.

anterior drawer- tests the anterior talar fibular ligament (ATFL). knee at 90 degrees, foot in relaxed position. cup heel with one hand and push on tibia posteriorly-positive is 2mm of subluxation relative to the other foot or visible dimpling of the anterior skin.

Talar tilt- tests ATFL and calcaneofibular ligament (CFL)-in same position as above-forced inversion of foot is applied- positive if there is obvious joint laxity relative to the other side or no passive resistance to forced motion-indicates rupture of ATFL and CFL. can do with forced eversion which tests the stability of the deltiod ligament.

Fibular compression: tests the tiobiofibular syndesmotic ligament. Same position as before but dorsiflex foot. squeeze tibia and fibula together 6-8 inches below knee. Positive tests if there is pain in the ankle.

Thompson's tests- prone with knee flexed squeeze gastroc and soleus in midcalf. if no plantarflexion-torn achilles tendon.

Classification

1. Class I
   1. mild pain,swelling can bear weight, negative stress test-
   2. Treatment = RICE and f/u in 7 days.
2. Class II
   1. mod pain, swelling, difficulty bearing weight, pos ant drawer (4-14 mm), pos talar tilt (5-15 degrees)
   2. Treatment: rigid splint, crutches, <7 day f/u.
3. Class III
   1. severe pain, unable to bear weight, lot of swelling. ant drawer >15 mm, talar tilt >15 degrees
   2. Treatment: rigid splint, crutches, f/u in <7 days.

ATFL most common ligament (80% of inversion injuries).

eversion injuries- deltoid ligament rarely isolated tear-usually avulsion Fx of medial malleolus. syndesmotic sprains more common than deltoid injuries (and more easily missed).

grade 2 and 3 eversion injuries are often placed in a short leg walking cast for 6-8 weeks.

Causes of Chronic Pain after Healing

1. soft tissue problems
   1. synovial impingement syndromes
   2. loose bodies in the joint
   3. proneal tendon subluxation
2. bony problems
   1. osteochondral Fx of talar dome
   2. lateral or posterior fx of talus
   3. anterior fx of calcaneus

Syndesmotic Sprain

(High Ankle)

Diagnosis

1. Positive squeeze test
2. TTP distal tibiofibular joint

Treatment

1. Treat as sprain, f/u ortho/sports
2. possible surgical repair if refractory to conservative management

See Also

• Maisonneuve
• Pilon Fx
• Ankle (Ottowa)
• Ankle Fracture