Incidence of Carpal Coalition in the Pediatric Population.

BACKGROUND: Carpal coalitions (CCs) result from the failure of segmentation of the carpal anlage in early development. In the adult population, CC is usually described as an asymptomatic radiographic finding. Data on CC in the pediatric population are limited. This study examines the prevalence of CC in the pediatric population and characterizes the presentation and associated musculoskeletal conditions.

METHODS: We used a cross-sectional design to assess data collected from all patients seen in our institution and associated facilities from August 2004 through February 2013. In total, 20,929 patients had an upper extremity x-ray taken that included the wrist. A natural language software recognition program for key words identified 104 patients with CC. Period prevalence and demographic and radiographic data were estimated using frequency and percentages.

RESULTS: The period prevalence of CC in this population was 5:1000. The initial age at the radiologic CC presentation varies between types. The most common CC (luno-triquetral, 69.2%) had a mean age at presentation of 12 y 11 mo. The second most frequent CC (capito-hamate, 17.2%) had a mean age at presentation of 8 y 2 mo. CCs were more prevalent among African American children; however, capito-hamate coalitions (the second most common coalition) were more often observed in whites. CC was symptomatic in 2 patients. Thirty-nine patients had associated conditions such as skeletal dysplasia and limb deformity, and most of these patients were diagnosed with capito-hamate coalitions.

CONCLUSIONS: The period prevalence of CC in this pediatric population is 5:1000. Similar prevalence has been reported in other studies. Although the prevalence of CC is comparable by sex, it is most common among African American children. The most common CC is luno-triquetral followed by capito-hamate. Capito-hamate coalitions were more common among patients with associated conditions and were diagnosed at a younger age relative to other subtypes in our group.

LEVEL OF EVIDENCE: Level IV-prognostic case series.