Hyperactivity and the psychological burden of Perthes disease: a case-control study

Legg-Calve-Perthes Disease (LCPD) is a childhood precursor to hip osteoarthritis, for which the etiology is unknown. There is a widespread belief that affected individuals are "hyperactive," propagating a theory that such children may have sustained an epiphyseal injury that precipitated the onset of LCPD. This study seeks to quantify the association with hyperactivity, and the wider psychological burden of the disease.

A case-control study was conducted among 146 cases of LCPD and 142 hospital controls, frequency matched by age and sex. Psychological domains were measured using the Strength and Difficulties Questionnaire. Adjustment was made for age, sex, and socioeconomic deprivation. Results were stratified by the time elapsed since LCPD was diagnosed.

Significant associations (P<0.05) existed with the majority of the psychological domains captured by the Strength and Difficulties Questionnaire [odds ratio (OR) for "high" level of difficulties-Emotion OR 3.2, Conduct OR 2.1, Inattention-Hyperactivity OR 2.7, Prosocial Behavior OR 1.9]. Hyperactivity was especially marked among individuals within 2 years of diagnosis (OR 8.6; P<0.001), but not so among individuals over 4 years from diagnosis. Emotional symptoms persisted long after resolution of the active phase of disease.

There was a marked psychological burden among individuals with LCPD, which was most marked amongst individuals with a recent diagnosis. The breadth and inferred temporality of these disturbances may be a function of the disease process, through restriction of activities and disability, or may be a fundamental disease characteristic related directly to disease or to its etiological determinant.