Avascular necrosis of the head in paediatric hip fractures, an inevitable complication

Hip fracture in patients with open physis is known for its low occurrence rate. However, despite its rare presentation, this type of fracture is known for its serious complications. Avascular necrosis (AVN), coxa vara, premature closure of the physis and secondary displacement are major complications that will determine prognosis. AVN with associated growth disturbances is the most serious complication and also an influential factor in predicting the outcome. This paper reports a retrospective study of 20 children who sustained a hip fracture according to Delbet type I-IV followed for at least 2 years. AVN was observed in four patients (21%), two of whom developed a complete AVN Ratliff type I within 6 months, requiring reconstructive surgery. Non-AVN-associated coxa vara (n=5) and re-displacement (n=3) are complications with less serious effects on outcome. Our clinical results regarding AVN and its risk factors - such as age group and type of fracture - are comparable to the results of other documented reports. An overview of both avoidable and inevitable AVN risk factors, including possible preventative measures, is presented in this report.