The Epidemiology of Slipped Capital Femoral Epiphysis in Children and Adolescents: A Systematic Review of Risk Factors and Incidence Across Populations.

Background: Childhood obesity is a growing global health crisis with significant health and orthopedic complications such as slipped capital femoral epiphysis (SCFE), a hip disorder characterized by the displacement of the metaphysis relative to the epiphysis. SCFE always requires surgical intervention to prevent severe outcomes such as avascular necrosis, gait abnormalities, and lifelong disability and deformity. Obesity is a well-established risk factor for SCFE; however, emerging evidence suggests that elevated leptin levels may independently contribute to the development of SCFE, regardless of obesity status. This systematic review synthesizes geographic, socioeconomic, age, and sex-related trends in SCFE incidence among children with obesity.

Methods: Searches of Embase, OVID Medline, and Emcare databases were performed from inception through October 1, 2024. Observational studies reporting the incidence of SCFE in children and adolescents with obesity (aged ≤18 years) across various geographic populations were included. Studies involving children with other chronic health conditions or animal studies on the physis were excluded. Study quality was evaluated using the methodological index for nonrandomized studies scoring system. Descriptive statistics were presented as absolute frequencies with percentages or as weighted means with corresponding measures of variance where applicable.

Results: Fifteen studies (5,467 patients) from North America, Europe, Asia, and Oceania met inclusion criteria. SCFE patient samples ranged from 55 to 1,630, with some larger cohorts monitoring multiple medical conditions. The mean age was 12.0 years (SD = 0.4), and male-to-female ratios ranged from 1.43:1 to 3.12:1. SCFE incidence varied by region, from 50.5 per 100,000 (Sweden) to 0.33 per 100,000 (South Korea), with a pooled incidence of 9.62 per 100,000. Overweight prevalence was highest in Sweden (66%) and South Korea (67.6%) and lowest in Japan (11.8%). Unilateral SCFE predominated (68.4% to 90.6%). In situ screw fixation was the most common treatment, with 1 study reporting intertrochanteric osteotomy.

Conclusion: Geographic variation in SCFE incidence suggests multifactorial influences beyond obesity, including socioeconomic factors, healthcare access, and genetic predisposition. Limited high-quality comparative studies and inconsistent BMI criteria highlight the need for further research to clarify SCFE risk factors.

Level of evidence: Level IV, systematic review. See Instructions for Authors for a complete description of levels of evidence.