O0814 Oct.3: 3:52pm - Genu Valgum and Obesity in the Pediatric Patient

Background:

The increased incidence of obesity in the pediatric population is accompanied by increased incidence and severity of lower extremity pathology. Genu valgum is thought to improve as children grow, however, our clinical observations suggest that in overweight or obese children, the diagnosis of genu valgum portends an altered disease trajectory. Where genu valgum in a normal weight child generally follows a mild course, we hypothesize that children with increased body mass index are more likely to experience long term sequelae and the need for surgical intervention.

Methods:

A retrospective chart review of patients with genu valgum diagnoses over a span of 19 years was performed. Inclusion criteria specified patients with a genu valgum diagnosis before age 18. Exclusion criteria disqualified patients that were misdiagnosed, not seen within the Geisinger hospital system, deceased before age 18, or had insufficient follow-up. Demographic information for these patients was collected as well as the cause of genu valgum diagnosis, and various markers for the severity of disease.. Comparisons were analyzed using Fisher’s exact or chi-square tests for categorical data and the Wilcoxon test for non-parametric continuous data. Logistic regression was used to calculate the area under the curve (AUC) for the receiver operating characteristics (ROC) curve.

Results:

554 children met inclusion criteria for the study out of 604 charts reviewed. Of these 554 patients, 39 of them required surgical intervention for their genu valgum with the majority of these being epiphysiodesis surgery. A majority of the patients who had surgery were in the obese category (63.6%) and all of the patients who underwent surgery were male. A comparison of two BMI percentile categories showed a higher number of initial visits (over 5 initial visits for knee-pain) in the combined overweight and obese categories as compared to the normal weight group (11.6% vs. 2.4%, p = 0.0068, Table 1). The number of surgeries was higher in the overweight and obese group as compared to the healthy weight group (p = 0.0268, Table 1) and a higher number of patients had surgery in the combined overweight and obese categories than the healthy weight category (6.9% vs. 1.9%, p = 0.0188, Table 1). The receiver operating characteristics curve suggests BMI is a strong predictor of surgical intervention (area under curve 0.897, Figure 1).

Conclusion:

Historically, most diagnoses of genu valgum in children run an indolent course without the need for surgical intervention. Our data analyses suggest that the outcome for this disease is likely to change with the coexistence of elevated BMI. The relationship between obesity and the severity of genu valgum in the pediatric population appears to be a prognostic indicator of a more challenging disease course complicated by an increased likelihood for surgical intervention.