title: [Legg-Calvé-Perthes disease].
abstract: BACKGROUND
  Legg-Calvé-Perthes disease is characterized by avascular necrosis of the head of the femur. This article deals with the epidemiology, possible causes, treatment and prognostic factors connected with the disease.
  
  
  METHODS
  The article is based on a non-systematic literature search and own clinical practice, with special emphasis on a Norwegian countrywide study of children with Legg-Calvé-Perthes disease.
  
  
  RESULTS
  The incidence of Legg-Calvé-Perthes disease varies in different countries and regions. Those who are older than six years at the time of diagnosis and have over 50% femoral head necrosis have a worse prognosis than younger children where the necrosis is less extensive. Treatment has been discussed extensively over the past 100 years, and still varies considerably. The Norwegian countrywide investigation showed that the results in children who were over six years at the time of diagnosis and had more than 50% femoral head necrosis were significantly better after varus femoral osteotomy than after physiotherapy or orthosis. This agrees with the only other prospective study that has been published.
  
  
  CONCLUSIONS
  Operative treatment should be considered in children who are six years old or older and have over 50% femoral head necrosis when the diagnosis Legg-Calvé-Perthes disease is made. Those who are younger than six years at the time of diagnosis or who have less than 50% femoral head necrosis should be treated symptomatically. Abduction orthosis has no place in the treatment of Legg-Calvé-Perthes disease.
authors: Ortopedisk avdeling, Oslo universitetssykehus, Norway. ola.wiig@oslo-universitetssykehus.no
authors: Ola
authors: O
authors: Wiig
authors: Svein
authors: S
authors: Svenningsen
authors: Terje
authors: T
authors: Terjesen