Seasonal Variations in Slipped Capital Femoral Epiphysis

Slipped capital femoral epiphysis (SCFE) is a common adolescent hip disorder occurring during the pubertal growth spurt, and prior studies have demonstrated regional seasonal variation in presentation volume. The relationship between seasonality, socioeconomic deprivation, and disease severity remains incompletely characterized. This study investigated whether SCFE presentation volume demonstrates seasonal variation and whether seasonality is associated with socioeconomic deprivation, body mass index (BMI), and radiographic severity.

We retrospectively reviewed children newly diagnosed with SCFE at a single institution in Wisconsin (USA) between January 2012 and March 2024. Variables included age, sex, race, Area Deprivation Index (ADI), BMI, month of symptom onset, Southwick slip angle, stability, chronicity, and symptom duration. Presentation volume was analyzed using 3-month rolling averages and sinusoidal regression with 12-month periodicity. Associations among ADI, BMI, and slip angle were assessed using linear regression and Spearman's correlation.

In total, 122 of 160 patients met the inclusion criteria. SCFE presentation volume demonstrated significant seasonality (p < 0.05). Lower-volume months were associated with higher neighborhood deprivation and greater radiographic severity (p < 0.05). ADI correlated with slip angle (r = 0.29, p < 0.05) and BMI (r = 0.33, p < 0.05), whereas BMI was not significantly associated with slip angle. Chronic slips demonstrated greater slip angles than acute presentations (p < 0.05).

SCFE presentation volume in Wisconsin follows a significant seasonal pattern, and social determinants of health may influence the timing of presentation and disease severity.