title: High revision rate but good healing capacity of atypical femoral fractures. A comparison with common shaft fractures.
abstract: BACKGROUND
  Healing of complete, atypical femoral fractures is thought to be impaired, but the evidence is weak and appears to be based on the delayed healing observed in patients with incomplete atypical fractures. Time until fracture healing is difficult to assess, therefore we compared the reoperation rates between women with complete atypical femoral fractures and common femoral shaft fractures.
  
  
  METHODS
  We searched the orthopaedic surgical registry in Östergötland County for patients with subtrochanteric and femoral shaft fractures (ICD-10 diagnosis codes S72.2, S72.3 and M84.3F) between January 1st 2007 and December 31st 2013. Out of 895 patients with surgically treated femoral shaft fractures, 511 were women 50 years of age or older. Among these we identified 24 women with atypical femoral shaft fractures, and 71 with common shaft fractures.
  
  
  RESULTS
  Reoperations were performed in 6 and 5 patients, respectively, odds ratio 4.4 (95% CI 1.2 to 16.1). However, 5 reoperations in the atypical fracture group could not be ascribed to poor healing. In 3 patients the reoperation was due to a new fracture proximal to a standard intramedullary nail. In 2 patients the distal locking screws were removed due to callus formation that was deemed incomplete 5 months post-operatively. The one patient with poor healing showed faint callus formation at 5 months when the fracture was dynamised and callus remained sparse at 11 months. Among patients with common shaft fractures, 2 reoperations were performed to remove loose screws, 2 because of peri-implant fractures and 1 reoperation due to infection.
  
  
  CONCLUSIONS
  Reoperation rates in patients with complete atypical femoral fractures are higher than in patients with common shaft fractures. The main reason for failure was peri-implant fragility fractures which might be prevented with the use of cephalomedullary nails at the index surgery. Fracture healing however, seems generally good. A watchful waiting approach is advocated in patients with fractures that appear to heal slowly.
authors.affiliation: Department of Experimental and Clinical Medicine and Department of Orthopedic Surgery, Faculty of Health Science, Linköping University, Linköping SE-581 85, Sweden. Electronic address: Jorg.schilcher@regionostergotland.se.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schilcher
mesh_terms: D000368:Aged; D005260:Female; D005264:Femoral Fractures / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary; D017102:Fracture Healing; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D012086:Reoperation / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome; D016474:Weight-Bearing
keywords: Atypical femoral fracture; Bisphosphonate; Delayed healing; Fracture healing