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 1995- 1996 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.