Slipped Capital Femoral Epiphysis in Children without Obesity

To evaluate rates and characteristics of slipped capital femoral epiphysis (SCFE) in children who are not obese to prevent missed diagnoses and subsequent complications.

A multicenter, retrospective review identified all patients with SCFE from January 1, 2003 to December 31, 2012. Patients were excluded if they received previous surgery at an outside institution, had no recorded height and weight, or had medical co-morbidity associated with increased risk of SCFE. Body mass index (BMI) percentile for age was calculated and categorized for each patient (patients without obesity vs with obesity).

In total, 275 patients met inclusion criteria. Average BMI was 91.2 percentile (range: 8.4-99.7). Thirteen percent (34 patients) were considered "normal weight" (BMI 5%-85%), 17% (48 patients) were considered "overweight" (BMI 85%- 95%), and 70% (193 patients) were considered "obese" (BMI >95%). Average BMI percentile was higher in male than female patients (93.2 ± 12.7 vs 88.5 ± 21.4, P = .034). Patients without obesity were older compared with patients with obesity (12.2 ± 1.7 vs 11.7 ± 1.6 years, P = .015). Fewer patients without obesity were seen at the hospital in the southwest. The southwest had fewer patients without obesity than the northeast (18.3% vs 36.1%, P = .002). Patients without obesity were more likely to present with a severe slip as graded by Wilson percent displacement (27.2% vs 11.4%, P = .007) and an unstable slip (32.9% vs 14.7%, P = .001).

Rates of nonobese SCFE in this study are higher than reported in the previous literature. Normal weight patients with SCFE are more likely to be older, female, and present with a severe and unstable SCFE.