Perthes' disease in Kurunegala.
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D005271:Femur Head Necrosis / Q000453:epidemiology*; D006801:Humans; D007873:Legg-Calve-Perthes Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D008297:Male; D012737:Sex Factors; D013188:Sri Lanka