Unravelling the enigma of Perthes disease

Abstract

Perthes disease is an idiopathic avascular necrosis of a juvenile hip. Although 2010 marked a century since it was first described, the aetiology remains unknown. It is suggested that adverse socioeconomic circumstances may be a key precipitant. This work describes recent studies that explore the disease epidemiology. Descriptive studies include a case register from Merseyside, hospital discharge data from Scotland, analysis of the world’s largest community disease register (General Practice Research Database [GPRD]) and a systematic review of incidence. Analytical studies include a nested case-controlled study in the GPRD and a hospital case-controlled study. The studies demonstrated a striking north–south divide in the UK incidence of Perthes disease, similar to that seen in many adult diseases. There was a sustained fall in disease frequency in all studies, with a narrowing of the north–south divide. There was a strong association with area deprivation, independent of living in an urban environment. Internationally, equatorial regions were unaffected by disease and northern Europe had the highest incidence, which was primarily a function of race although latitude was an independent predictor. Individual characteristics associated with the disease were congenital anomalies of the genitourinary tract and a structural abnormality of arterial calibre. Despite a falling incidence, Perthes disease remains an important cause of child morbidity and exemplifies socioeconomic inequalities. A deprivation-related exposure, acting early in development, appears critical. The aetiological factor in Perthes disease remains elusive but it is likely that unravelling this enigma may unlock additional secrets pertaining to the developmental origins of this and other diseases.

Skeletal immaturity, rostral sparing, and disparate hip morphologies as biomechanical causes for Legg‐Calvé‐Perthes' disease

“…The association between socioeconomic status (SES) deprivation and Perthes' disease is strong (Gordon et al, ; Sharma et al, ; Perry et al, ,2012a,b; Perry, ,), while the relationship between second‐hand smoking and Perthes' disease is more contested (García Mata et al, ; Gordon et al, ; Bahmanyar et al, ). In early studies investigating the relationship between SES and Perthes' disease, a positive correlation was discovered between people who lived in urban regions, lower SES, and Perthes' disease.…”

Controlled trials of vitamin D, causality and type 2 statistical error

“…Perthes’ disease of bone involves disrupted blood supply to the head of the femur followed by distortion of the joint, pain and limping. The aetiology of Perthes’ disease is not clearly understood but is known to involve a north–south gradient and a deprived environment which is consistent with possible vitamin D deficiency ( 12 ) . A trial of vitamin D for Perthes’ disease might possibly be beneficial and if positive clarify the aetiology, but a null result would tell us nothing useful about causation because deficiency might have been caused by an earlier lesion that is irremediable by the time vitamin D therapy is started.…”

<p>Exploring how to evaluate a qualitative patient-centered outcome measure: literature review and illustrative example – a Perthes child-friendly measure</p>

“…Perthes’ disease is a condition that affects predominantly young male children presenting between 4 and 7 years of age 42. Commonly reported outcomes are radiographic, focusing on the shape and congruency of the femoral head 43.…”