Pediatric emergency medicine trisk 0794 0794

CHAPTER 40 ■ INJURY: ANKLE
FRANCES TURCOTTE BENEDICT, ANGELA C. ANDERSON

INTRODUCTION
Approximately 26% of sports-related injuries in school-aged children involve the
ankle. It is often difficult for children to localize pain, therefore young children
with ankle injuries may complain of pain anywhere from their mid-calf to their
toes. Conversely, pathology in the lower leg and foot can cause referred pain to
the ankle.
The ankle joint is composed of three bones: the tibia, the fibula, and the talus.
The bony prominence of the distal fibula constitutes the lateral malleolus,
whereas the prominence of the distal tibia forms the medial malleolus. The
physes are located 1 to 2 fingerbreadths above the distal ends of the tibia and the
fibula.
The ankle ligaments are attached to the epiphyses. The distal fibular physis is
the most commonly injured growth plate in the lower extremities. It is second
only to the distal radius in the incidence of physeal injuries.
Growth plates and bones are weaker than ligaments. Consequently, ankle
trauma in preadolescent children is more likely to cause fractures of the physis
and the adjacent epiphysis and/or metaphysis than ligamentous injuries or sprains,
although recent MRI-based studies have had conflicting findings.

DIFFERENTIAL DIAGNOSIS
A number of traumatic injuries may cause ankle pain (Table 40.1 ). Although
trauma is the most common cause of ankle pain in children, infectious,
rheumatologic, inflammatory, neoplastic, and hematologic abnormalities also
should be considered (Table 40.2 ) because in some cases trauma may merely
exacerbate pain in children with underlying conditions. Again, keep in mind that
a complaint of ankle pain may result from a lesion anywhere between the knee
and the toe, particularly in preverbal children. The most common injuries vary
according to age (Table 40.3 ).

ANKLE FRACTURES
Ankle fractures are among the most common injuries of the lower extremity in
children. Fractures of the ankle account for up to 40% of all injuries in skeletally
immature athletes. The system used to classify ankle fractures in children differs
from the one used in adults because of the presence of growth plates and the