The Foot and Ankle: Congenital and Developmental Conditions

Abstract

The radiographic evaluation of congenital and developmental abnormalities of the foot and ankle provides critical information to guide orthopedic treatment. This chapter begins by discussing the anatomy and normal variants of the ankle. Congenital and developmental abnormalities of the ankle are explored, including ball-and-socket ankle. The development and normal variants of the pediatric foot are then discussed. After describing radiographic techniques for imaging the foot, the chapter presents methods to evaluate and vocabulary to describe foot alignment. This is then applied to a broad spectrum of structural deformities of the foot, including clubfoot, cavus deformity, and multiple types of fl atfoot (including tarsal coalition). A discussion of forefoot alignment follows, and the chapter concludes with a brief discussion of congenital foot malformations.In order to provide useful interpretations of foot and ankle radiographs, the radiologist must have a thorough knowledge of the many normal variants that affect this area, recognizing those that may mimic or obscure pathology. Analysis of alignment requires a careful, systematic approach, along with a clear understanding of normal alignment, the wide variety of possible deformities, and the many ways they may combine to create unique constellations of pathology.

Normal Development and Variants in Pediatric Bone

“…제5중족골 기저부의 견열 골절과의 감별이 필요한데, 견인골단은 중족골의 장축에 평행한 반면 힘줄 부착 부위가 당져져서 발생하는 것으로 알려져 있는 견열 골절은 중족골에 수평 방향인 것이 특징이다. 정상적으로도 제5중족골 견인골단의 골단판이 넓게 보일 수 있기 때문에 견인골단의 박리가 의심된다면 동일한 자세로 촬영한 반대편 영상과 비교하여 견인골단의 골단판이 넓어진 것을 확인하는 것이 진단에 도움이 된다( 35 36 ).…”

Pediatric Foot: Development, Variants, and Related Pathology

“…Many congenital and developmental conditions cause foot alignment disorders in children, and a thorough treatment of the topic could occupy an entire review article or book chapter. 39,40 However, most congenital foot deformities can be evaluated by assessing a few relationships on AP and lateral weight-bearing or simulated weight-bearing radiographs. In this section we first describe correct radiographic technique and then review three relationships, which, if assessed, can diagnose most congenital foot deformities.…”

“…For the AP simulated weight-bearing radiograph in an infant or older child who cannot bear weight, the foot is placed plantigrade on the image detector with the central beam angled approximately 15 degrees. 40,41 The lateral simulated weight-bearing view can be obtained Fig. 9 Talocalcaneal coalition in a 14-year-old girl.…”

“…Some draw the line through the central axis of the calcaneus and others along the undersurface of the calcaneus. 40,42 In the newborn, this angle normally ranges between 60 and 90 degrees. 41 If there is excessive plantar flexion of the anterior calcaneus, termed an equinus deformity, this angle will measure > 90 degrees.…”

“…As with the axis of the calcaneus on the lateral view, there is variability in how authors draw the axes of the talus and calcaneus on the AP view and the talus on the lateral view, with some drawing a central axis line, and others, particularly in young children with smaller ossifications, drawing the talar axis parallel to the medial cortex of the ossification center and the calcaneal axis parallel to the lateral cortex of the ossification center. 40 In the newborn, the talocalcaneal angle averages 40 degrees on both the AP and lateral projections. 42 On the AP projection, this value decreases throughout childhood to a value 18 degrees by 9 years of age.…”