Rockwood Adults CH64

2835

CHAPTER 64 • Ankle Fractures

Pronated foot

External rotation

Abduction

I

I

Isolated medial malleolus or deltoid ligament rupture

Isolated medial malleolus or deltoid ligament rupture

Medial malleolus fracture or deltoid rupture

Medial malleolus or deltoid

II

II

Chaput's tubercle or anterior tib-fib ligament

Chaput's tubercle or anterior tib-fib

III

III

Transverse or laterally comminuted fibula with medial injury. Anteriolateral tibial

Medial injury with a high fibula fracture

impaction is also possible

IV

Similar to stage III with a posterior malleolus or tib-fib ligament injury

Posterior malleolus or

posterior tib- fib ligament

Figure 64-8.  ( Continued ) E: A pronated foot sustains either an exter- nal rotation or abduction force and creates the successive stages of injury shown in the diagram. The PER mechanism has four stages of injury, and the PAB mechanism has three stages.

E