Osteochondritis dissecans of the ankle in children and adolescents: demographics and epidemiology.

BACKGROUND

Osteochondritis dissecans (OCD) of the ankle is a disorder of the talar or distal tibial subchondral bone and articular cartilage whose incidence in children is not clearly known.

PURPOSE: To assess the demographics and epidemiology of OCD of the ankle in children.

STUDY

DESIGN

Descriptive epidemiologic study.

METHODS

A retrospective chart review of an integrated health system was conducted on patients with ankle OCD aged 2 to 19 years from 2007 to 2011, with >1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. Ankle OCD incidence was determined for the group as a whole and by both sex and age group (divided into age groups of 2-5, 6-11, and 12-19 years). The risk for ankle OCD for age group, sex, and ethnicity was assessed using multivariate logistic regression models.

RESULTS

A total of 85 patients fit the inclusion criteria, and 71.8% of lesions found were in the medial talus, 56.5% of lesions were right sided, and none were bilateral. No ankle OCD lesions were found in 2- to 5-year-olds. The incidence of ankle OCD in patients aged 6 to 19 years was 4.6 per 100,000 overall and 3.2 and 6.0 per 100,000 for male and female patients, respectively. Patients aged 12 to 19 years represented the vast majority of those with OCD, with an incidence of 6.8 per 100,000 compared with 1.1 per 100,000 in those 6 to 11 years of age. In those aged 6 to 11 and 12 to 19 years, female patients had a respective incidence of 1.5 and 8.9 per 100,000, whereas male patients had a respective incidence of 0.7 and 4.8 per 100,000. The overall female/male ratio of ankle OCD was 1.6:1. Multivariate logistic regression analysis revealed a 6.9 times increased risk for ankle OCD in patients aged 12 to 19 years compared with those aged 6 to 11 years (95% CI, 3.8-12.5; P < .0001), and female patients had a 1.5 times greater risk for ankle OCD than male patients (95% CI, 1.0-2.3; P = .06). On the basis of race and ethnicity, non-Hispanic whites had the highest relative risk for disease and African Americans the lowest risk.

CONCLUSION

In this population-based cohort study of pediatric ankle OCD, female patients had a greater incidence of OCD and a 1.5 times greater risk for ankle OCD compared with male patients. Teenagers had nearly 7 times the risk for ankle OCD compared with children 6 to 11 years of age.