Objective To examine the prevalence of scoliosis in patients with Fontan circulation.

Design Retrospective cohort (case-only), level IV study.

Setting A comprehensive paediatric centre.

Methods We examined the radiographs of 194 patients who underwent Fontan completion surgery between 1998 and 2011 at a median age of 1.3 years.

Main outcome measure We collected data on the age at the last available radiograph and when scoliosis was diagnosed; we used the first available radiograph with scoliosis. We also measured the magnitude and direction of the spinal curve in patients with scoliosis.

Results Median age at radiography was 3.4 years. Nineteen patients (9.8%) developed scoliosis; none of them underwent thoracotomy. Most of the patients with scoliosis were older than 5 years of age at scoliosis diagnosis and the female to male ratio was 5 : 3. The major curve was right thoracic in 12 patients (63.2%), left thoracic in four patients (21.1%) and high thoracic in three patients (15.8%). For every 1 year increase in age there was a 27% increased risk of developing scoliosis.

Conclusions There was a high prevalence of scoliosis in patients with Fontan circulation. We recommend interdisciplinary monitoring of these patients to diagnose spinal curve deformities in a timely manner.