Orthopedic complications of overweight in children and adolescents

Abstract

Objective: Few studies have quantified the prevalence of weight-related orthopedic conditions in otherwise healthy overweight children. The goal of the present investigation was to describe the musculoskeletal consequences of pediatric overweight in a large pediatric cohort of children that included severely overweight children.

Methods: Medical charts from 227 overweight and 128 nonoverweight children and adolescents who were enrolled in pediatric clinical studies at the National Institutes of Health from 1996 to 2004 were reviewed to record pertinent orthopedic medical history and musculoskeletal complaints. Questionnaire data from 183 enrollees (146 overweight) documented difficulties with mobility. In 250, lower extremity alignment was determined by bilateral metaphyseal-diaphyseal and anatomic tibiofemoral angle measurements made from whole-body dual-energy x-ray absorptiometry scans.

Results: Compared with nonoverweight children, overweight children reported a greater prevalence of fractures and musculoskeletal discomfort. The most common self-reported joint complaint among those who were questioned directly was knee pain (21.4% overweight vs 16.7% nonoverweight). Overweight children reported greater impairment in mobility than did nonoverweight children (mobility score: 17.0 +/- 6.8 vs 11.6 +/- 2.8). Both metaphyseal-diaphyseal and anatomic tibiofemoral angle measurements showed greater malalignment in overweight compared with nonoverweight children.

Conclusions: Reported fractures, musculoskeletal discomfort, impaired mobility, and lower extremity malalignment are more prevalent in overweight than nonoverweight children and adolescents. Because they affect the likelihood that children will engage in physical activity, orthopedic difficulties may be part of the cycle that perpetuates the accumulation of excess weight in children.

FIGURE 1

Measurement of lower extremity alignment. Whole-body DXA scans were used to measure lower extremity alignment. The MDA was defined as the angle between a line through the metaphyseal beaks (dashed line) and a line perpendicular to the tibial shaft (A). The A-TFA was defined as the angle formed by lines through the tibial and femoral shafts (B). In these sample images, the lower extremities demonstrate a bilateral valgus alignment of 20 degrees in the left leg and 20 degrees in the right leg, according to MDA measurements.

FIGURE 2

Prevalence of fractures and musculoskeletal pain. The prevalence of chart-review documented fractures and complaints of musculoskeletal (MSK) pain at any anatomic location was significantly greater in overweight than in nonoverweight youth. ^aP < .01 (A). The prevalence of self-reported MSK complaints by a structured symptom questionnaire (B) also tended to be greater in the overweight group. Fracture history and history of leg pain were not assessed in the symptom questionnaire. Upper 95% CIs are shown.

FIGURE 3

Lower extremity alignment measurements in overweight and nonoverweight children. Linear correlations between BMI SD score for age and gender (BMI z score) and MDA (A) and A-TFA (B) as determined using DXA. (C) A significantly greater proportion of overweight children (□) had abnormal MDA and A-TFA angles compared with nonoverweight children (■). ^aP <.01; ^bP <.05. Upper 95% CIs are shown.