title: [Differences between transient osteoporosis of the hip and bone marrow edema associated with osteonecrosis of the femoral head].
abstract: OBJECTIVE
  To explore the differences between transient osteoporosis of the hip (TOH) and bone marrow edema (BME) associated with osteonecrosis of the femoral head (ONFH) in terms of clinical practice and imaging.
  
  
  METHODS
  From January 2006 to February 2008, 5 hips of TOH in 5 cases (1 male and 4 females, aged 29-42 years) and 67 hips of BME associated with ONFH in 63 cases (53 males and 10 females, aged 18-70 years) were analyzed. According to ARCO classification, there were 23 hips of stage II, 43 hips of stage III, and 1 hip of stage IV. The induced factors, the degree of pain, the duration of pain and commemorative symptoms were compared. The X-ray, MRI and ECT were also compared.
  
  
  RESULTS
  There were no differences in induced factors, the degree of pain, joint effusion and ECT between TOH and BME associated with ONFH. TOH had no risk factors, antecedent symptoms and commemorative pain. There were 2 hips with TOH which showed osteopenia on X-ray films. The location of edema was in the superior part or the whole femoral head. A total of 65 hips with BME associated with ONFH had related causes of disease, 10 had antecedent pain and 59 had change of hardening on X-ray films. The X-ray films showed sclerotic area and the edema changes on MRI surrounded the necrotic lesion. The pain just ameliorated when BME disappeared.
  
  
  CONCLUSIONS
  There are differences between TOH and BME associated with ONFH on symptoms, X-ray films and MRI.
authors.affiliation: Graduate School of Beijing Union Medical College, Beijing 100730, PR China.
authors.forename: Fengchao
authors.initials: F
authors.lastname: Zhao
authors.forename: Zirong
authors.initials: Z
authors.lastname: Li
authors.forename: Nianfei
authors.initials: N
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.forename: Liming
authors.initials: L
authors.lastname: Cheng
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Liu
authors.forename: Bailiang
authors.initials: B
authors.lastname: Wang
authors.forename: Shaohui
authors.initials: S
authors.lastname: Shi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001855:Bone Marrow Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D005260:Female; D005271:Femur Head Necrosis / Q000150:complications*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed