Incidence of Symptomatic Pediatric Tarsal Coalition in Olmsted County: A Population-Based Study.

BACKGROUND: Tarsal coalitions are an important reason for foot pain in children. Early estimates placed the prevalence at up to 2%, while more recent data suggest that it is as high as 11% to 13%. To our knowledge, there have been no population-based studies to determine the true incidence of symptomatic tarsal coalitions in a pediatric population. METHODS: A population-based database was used to identify all new diagnoses of symptomatic tarsal coalitions in children 18 years old or younger between 1966 and 2018. Patient records were reviewed for clinical data, and comparisons were made between the types and characteristics of the coalitions identified to determine differences in the affected populations. The annual age-specific, sex-specific, and type-specific incidence rates were estimated. RESULTS: During the study period, 58 patients with a total of 79 symptomatic tarsal coalitions were identified (annual incidence = 3.5 per 100,000 children). There were 43 calcaneonavicular (CN) coalitions (annual incidence = 1.9 per 100,000 children), 27 talocalcaneal (TC) coalitions (annual incidence = 1.2 per 100,000 children), as well as 9 other coalitions (7 talonavicular, 1 naviculocuboid, and 1 naviculocuneiform) (annual incidence = 0.4 per 100,000 children). The overall incidence peaked between the ages of 10 and 14 years for both boys and girls (8.1 per 100,000 and 7.4 per 100,000 children, respectively). Statistical differences were identified between the types of tarsal coalitions. TC coalitions present at an older age relative to CN and other coalitions (mean,13.9, 12.7, and 11.4 years, respectively; p = 0.02). While CN and TC coalitions were similar in composition (23% and 30%, respectively, were osseous as opposed to fibrocartilaginous), other coalitions were more likely to be osseous (78%) (p = 0.0035). Other coalitions were also less likely to require surgery than CN and TC coalitions (11%, 74%, and 56%, respectively; p = 0.0015). CONCLUSIONS: This population-based study demonstrates differences in the clinical presentation of tarsal coalitions and provides an estimate of the true incidence of symptomatic tarsal coalitions in a pediatric population.