Incidence of congenital clubfoot in Sweden

Background Idiopathic clubfoot is one of the most common congenital orthopedic problems. Nationwide studies of the incidence are scarce. We performed a prospective multicenter study in order to assess the cumulative incidence in Sweden over 2 consecutive years. Patients and methods 44 clinics identified as treating clubfoot reported new cases prospectively. The medical records of 280 children with clubfoot born during 19951996 were collected and analyzed with special reference to gender, regional distribution and seasonal variation. Results The average cumulative incidence of clubfoot during the study period was 1.4/10(3) (95% CI 1.2-1.6). Three-quarters of the cases were boys. In half of the cases both feet were affected. There was significant regional heterogeneity, but no seasonal variation in occurrence of clubfoot. Interpretation The cumulative incidence was higher than in earlier Scandinavian studies. Gender distribution and laterality were similar to those in previous reports. We found significant regional differences in incidence, but the cause of this observation must be investigated in greater depth.