title: Avascular necrosis of the femoral head in pertrochanteric fractures: a report of 8 cases and a review of the literature.
abstract: OBJECTIVE
  To evaluate patients with pertrochanteric fractures (Type 31A1 + 2 ASIF/OTA classification) treated surgically and who subsequently developed avascular necrosis of the femoral head (ANFH).
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Retrospective clinical study and analysis of the literature.
  
  
  METHODS
  From 1995 to 2003 the authors operated on 1,373 patients with pertrochanteric fractures. Eight patients with a mean age of 69 years (range, 52-78 years) subsequently developed ANFH.
  
  
  METHODS
  Five patients were treated with a dynamic hip screw (DHS), and 3 were treated with an intramedullary hip nail (IMHN).
  
  
  RESULTS
  All fractures in these 8 patients healed without complications in 3 to 4 months. Avascular necrosis of the femoral head developed 4 months to 4 years after the operation. Detailed analysis of these cases did not reveal any risk factors or errors in surgical technique to account for the ANFH. Results of a literature review of 41 cases in addition to our 8 cases give us reason to believe the etiology of postoperative AFNH following surgical treatment of pertrochanteric fractures is probable injury to the deep branch of the medial circumflex artery at time of fracture. Other possible risk factors include high-energy trauma, comminution, displacement of the fragments, and atypical fracture line.
  
  
  CONCLUSIONS
  ANFH develops in approximately 0.5-1% of all pertrochanteric fractures, mostly within 4 years after the injury and predominantly in patients older than 50 years of age. The diagnosis should be considered in patients who have undergone an operation previously and have symptoms that are unclear. Prevention of ANFH in these fractures includes an early reduction, stable fixation, and correct surgical technique.
authors.affiliation: Orthopaedic Department, 3rd Faculty of Medicine, Charles University, Prague, Czech Republic. bartonic@fnkv.cz
authors.forename: Jan
authors.initials: J
authors.lastname: Bartonícek
authors.forename: Vladimír
authors.initials: V
authors.lastname: Fric
authors.forename: Jirí
authors.initials: J
authors.lastname: Skála-Rosenbaum
authors.forename: Pavel
authors.initials: P
authors.lastname: Dousa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails; D005260:Female; D005265:Femoral Neck Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000209:etiology*; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors