karim Pisoudeh - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Kaveh Gharanizadeh - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Mohammad Reza Naderan - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Mohammadreza Sarshar - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Masoud Mirkazemi - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.
Hamed Tayebi - Bone and Joint Reconstruction Research Center, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, Iran.

Background: Bisphosphonate-associated atypical femoral fracture (AFF) is a rare and serious ‎condition with poorly understood characteristics and management. ‎Objectives: To evaluate the characteristic features and outcomes of AFF in a two-center cohort ‎study.‎Methods: In a retrospective survey, medical profiles of ۲۲ AFF patients, who have used ‎alendronate for > ۱۲ months, were reviewed. The demographic characteristics such as age, ‎gender, and BMI, the clinical features including symptoms, symptom duration, radiologic ‎characteristics including fracture site, the severity of the fracture, and contralateral involvement, ‎surgical characteristics including the type of surgery union period and postoperative ‎complications such as fixation failure, and union problems were extracted from the patients’ ‎profiles.‎Results: The study population included ۴ males and ۱۸ females with a mean age ‎of ‎۷۰.۶±۱۱.۹ ‎ years. ‎The mechanism ‎of fracture was falling down‎ in ۲۱ (۹۵.۵% ) patients. The ‎mean duration of ‎bisphosphonate consumption was ‎‎۳.۸±۲ ‎‎ years. Prodromal symptoms (pain and ‎limping) were recorded in ۱۲ (۵۴.۵۵%) ‎patients. ‎The fracture was in the femoral shaft in ۱۵ ‎‎(۶۸.۲%) and in the subtrochanteric‎‎ in ۷ (‎‎۳۱.۸%) patients. ‎The fixation device was ‎the ‎intramedullary nail in ۱۸ (۸۱.۸%) and plate in ۴ (۱۸.۲%) patients. ‎The mean union period was ‎‎۸.۳±۲.۸ ‎months. Union complications (delayed or ‎nonunion) occurred in ۶ (۲۷.۳%) patients. ‎Fixation failed in ۵ (۲۲.۷%) patients (۳ nails and ۲ ‎plate fixation).‎Conclusions: AFF is associated with a prolonged union. ‎The intramedullary nail provides a more ‎secure fixation. Prodromal symptoms could be used for earlier detection of patients. ‎

Atypical femoral fracture, bisphosphonate, alendronate, Surgery, outcome.‎