Avascular necrosis after minimally displaced talus fracture in a child.

This is a case report of a delayed diagnosis in a 5 year old child who sustained a minimally displaced fracture of the proximal or posterior aspect of the talar neck of the left foot with no subluxation at the subtalar or ankle joint of his left talus. Avascular necrosis (AVN) appeared 6 months after the injury. The further course was protracted with another 12 months of non-weight bearing. The case was followed until 36 months after the injury with nearly full functional recovery. An extensive literature review revealed a calculated incidence of AVN after reportedly non-displaced talus fractures in children of 16 per cent which is considerably more than is reported in adults. Nearly half of all reported cases occurred after the fracture had been missed initially. 8 of 11 cases with reported age occurred between 1 and 5 years. No child was older than 9 years, which indicates that the immature talus may be more prone to AVN. Some possible causes for the higher incidence of AVN in children with non-displaced talus fractures are discussed. Prolonged non weight-bearing cannot be recommended, since it reportedly does not alter the course of the disease.