Incidence of Legg-Calvé-Perthes Disease in Crete (2021-2024): A Prospective Population-Based Epidemiological Study...

Legg-Calvé-Perthes disease (LCPD) is an uncommon pediatric osteonecrosis of the femoral head with substantial geographic variation in reported incidence. This study estimated the population-based incidence of LCPD in Crete (Greece) and contextualized findings through a narrative review of contemporary international literature.

We conducted a population-based prospective study of children aged 4-16 years in Crete between 2021 and 2024. Disease incidence was calculated using age-specific annual population counts and expressed per 100,000 child-years at risk. Annual population denominators were obtained from the Hellenic Statistical Authority. Incidence rates (per 100,000 child-years) and their 95% confidence intervals (CIs) were calculated assuming a Poisson distribution. In parallel, a narrative review (January 2015-September 2025) was conducted in PubMed/MEDLINE and Ovid to identify population-based studies reporting LCPD incidence or epidemiology following predefined search and selection criteria.

Over the four-year study period, a total of 401,900 child-years at risk were recorded, during which a total of 10 children were diagnosed with LCPD in Crete (11 affected hips; one bilateral case), yielding an overall hip-based incidence of 2.74 per 100,000 child-years (95% CI: 1.37-4.88). Annual incidence was 4.83 per 100,000 child-years in 2021 and approximately 2.00 per 100,000 child-years in 2022-2024. The mean age at presentation was 6.50 years, with a male predominance. The literature review identified eight eligible studies demonstrating marked international heterogeneity in incidence (0.2-29.2 per 100,000) and consistent male predominance.

LCPD incidence in Crete (2021-2024) was low and within the lower-to-mid range of international estimates. Findings reflect a population-based setting but should be interpreted cautiously due to limited case numbers and the absence of a control group.