Ankle Trauma

Question 1

Most appropriate stress radiograph to assess competency of deltoid ligament

Answer 1

External rotation stress radiograph (or gravity stress view)

Medial clear space of >5mm with ext rot applied is predictive of deep deltoid disruption

Question 2

Normal radiographic parameters to assess syndesmosis

Answer 2

Tibfib overlap - >6mm AP and >1mm Mortise

Medial clear space -

Question 3

Talocrural angle

Answer 3

Line drawn parallel to articular surface (sometimes perpendicular) of the distal tibia and another line through the tips of the malleoli
Normal 8-15 degrees (or 75-87 degrees is measured off vertical line)
Shortening of the lateral mal will increase TC angle

Question 4

What can block reduction of lateral talar displacement

Answer 4

Tibialis posterior tendon (Flexor retinaculum is torn)
Flexor digitorum longus
Joint capsule
Deltoid ligament