talipes
description
talipes or clubfoot is a common malformation involving the ankle joint and foot resulting in an abnormal position. the most common type is the equinovarus deformity in which there is plantar flexion of the foot and inversion of the sole. other types include: equinus, calcaneus, cavus, varus, calcaneovalgus, valgus, calcaneovarus and equinovalgus. the aetiology is multifactorial and can be the result of genetic or environmental factors. recently several studies have been published which suggest that talipes is more common after early amniocentesis. talipes can be an isolated finding, part of a syndrome, skeletal dysplasia or associated with chromosomal abnormality. prognosis will depend on the specific etiologic factor and associated anomalies. the male to female ratio is 2.5:1, it is reported more commonly in twins and no racial differences have been noted. an overall incidence of 0.43% has been suggested with 33% of cases having isolated clubfoot. in the remaining 67%, talipes was associated with other abnormality.
diagnosis
sonographic diagnosis is based on the knowledge of the relative position of the leg bones and foot axis. the first step is to image the lower leg longitudinally and determine the relative orientation of the foot in relationship to the leg. in talipes equinovarus, for example, the foot deviates medially at the ankle and remains fixed at a right angle to the distal tibia and fibula so the long axis of the foot resides in the same longitudinal plane as the tibia and fibula. the position and curvatures of the sole as well as the curvatures of the medial and lateral aspects of the foot will help in determining the type of deformity encountered. caution should be exercised in making a diagnosis of clubfoot since a normal fetus can hold the lower extremity in a ‘talipes-like’ position for a period of time. prolonged observation with emphasis on ankle motion will help in the differential diagnosis. a search for associated anomalies is mandatory.
differential diagnosis
there is a long list of syndromes and disorders that have talipes as a feature and the presence of associated anomalies should help in the differential diagnosis. (see associated syndromes) in rockerbottom foot (vertical talus) the sole is convex and there is a prominent heel. the normal fetus may display an abnormal foot position temporarily. prolonged monitoring and careful observation of joint mobility will eventually demonstrate normal position and movement.
sonographic features
long axis of tibia and fibula at the same plane as foot axis
medial rotation of the plane of the sole
extreme flexion of the foot
ankle joint abnormalities
limited joint mobility
associated syndromes
- agnathia,
- arthrogryposis multiplex congenita (amyoplasia congenita disruptive sequence ,classic arthrogryposis
- cardio-oculo-facial-skeletal (cofs or pena-shokeir type 11)
- diastrophic dysplasia
- distal arthrogryposis
- dyssegmental dysplasia
- escobar (multiple pterygium syndrome)
- freeman-sheldon
- larsen
- lethal multiple pterygium syndromes
- meckel-gruber
- oculo-auriculo-vertebral
- oligohydramnios sequence
- oromandibular-limb hypogenesis (moebius)
- roberts (sc phocomelia)
- spinal dysraphism/ neural tube defect
- triploidy
- trisomy 18
references
benacerraf b, et al prenatal ultrasound diagnosis of clubfoot radiology 155:211-213
benacerraf b antenatal sonographic diagnosis of congenital clubfoot. a possible indication for amniocentesis j clin ultrasound 14:703-706
chevernak f, et al antenatal sonographic diagnosis of clubfoot j ultrasound med 4:49-50
cowell hr, et al genetic aspects of clubfoot j bone joint surg 62:1381-1384
hashimoto be, et al sonographic diagnosis of clubfoot in utero j ultrasound med 5:81-83
furness me foot anomalies the fetus 2:4-754,780