title: [Asymptomatic osteonecrosis of the hip in HIV-infected patients].
abstract: BACKGROUND
  Osteonecrosis (ON) of the hip in human immunodeficiency virus (HIV)-infected patients has been related to corticosteroid use, dyslipidemia, alcoholism, lipodystrophy, antiretroviral drug use, and HIV infection, itself. The aim of this study was to evaluate the prevalence of silent ON of the hip in HIV-infected patients and its association with several risk factors.
  
  
  METHODS
  From a total of 1200 patients followed up at the HIV clinic of Xeral-Cies Hospital in Vigo (Spain), we selected those diagnosed with HIV infection before January 2006, aged 20-70 years, who came to the clinic during the period of March to May 2008. Patients with a diagnosis of ON of the hip and those with current symptoms were excluded. A magnetic resonance imaging (MRI) study of the hips was performed.
  
  
  RESULTS
  Ninety-seven Caucasian patients (68 men) with a median age of 44 years were included. ON of the hip was detected in 4 patients (4.1%), with bilateral involvement in 2 patients. All 4 patients were men, with a median age of 44.5 years. Several risk factors for ON of the hip were recorded in each patient. CD4 lymphocyte nadir (P=0.034), percentage of patients with CDC stage C (P=0.039), and number of patients with previous corticosteroid treatment (P=0.042) were significantly different between patients with ON of the hip and those with normal MRI findings.
  
  
  CONCLUSIONS
  The prevalence of asymptomatic ON of the hip in HIV-infected patients was 4.1%. The most important risk factors for developing this condition were corticosteroid treatment, lower CD4 lymphocyte nadir, and AIDS-defining disease. Antiretroviral treatment was not associated with osteonecrosis.
authors.affiliation: Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Complejo Hospitalario Universitario de Vigo, Hospital Xeral, Universidad de Santiago de Compostela, Vigo, Pontevedra, España.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Lamas
authors.forename: Antonio
authors.initials: A
authors.lastname: Ocampo
authors.forename: César
authors.initials: C
authors.lastname: Martínez-Vázquez
authors.forename: Celia
authors.initials: C
authors.lastname: Miralles
authors.forename: Rebeca
authors.initials: R
authors.lastname: Longueira
authors.forename: Mercedes
authors.initials: M
authors.lastname: Arias
authors.forename: Bernardo
authors.initials: B
authors.lastname: Sopeña
authors.forename: Alberto
authors.initials: A
authors.lastname: Rivera
authors.forename: Daniel
authors.initials: D
authors.lastname: Portela
mesh_terms: D000328:Adult; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006621:Hip Joint; D006801:Humans; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000453:epidemiology* / Q000209:etiology*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors