title: Predictors of atypical femoral fractures during long term bisphosphonate therapy: a case series & review of literature.
abstract: OBJECTIVE
  Bisphosphonates (BPs) are the most widely prescribed medicines for the treatment of osteoporosis because of their efficacy and favourable safety profile. There have been, several reports on an increased incidence of atypical femoral fractures after long term treatment with BPs. The objective of this study was to evaluate the clinical presentation including prodromal symptoms, skeletal radiograph findings, type and duration of BPs received and treatment outcome of patients who developed atypical femoral fractures during bisphosphonate therapy.
  
  
  METHODS
  In this retrospective study, eight patients with atypical femoral fractures were analysed based on clinical features, biochemical and radiological investigations.
  
  
  RESULTS
  Of the eight patients, who sustained atypical femoral fractures, six were on alendronate and two were on zoledronate therapy before the fractures. In addition to BPs, two patients were on long term corticosteroid therapy for rheumatoid arthritis and Addison's disease. Three patients had bilateral atypical femoral fractures. Except one, all of them had prodromal symptoms prior to fracture. Skeletal radiograph showed cortical thickening, pointed (beaking of) cortical margin and transverse fracture in meta-diaphyseal location. Serum calcium, phosphate, alkaline phosphatase (ALP) and intact parathyroid hormone (iPTH) concentrations were within the reference range in all patients.
  
  
  CONCLUSIONS
  Long term bisphosphonate therapy may increase the risk of atypical femoral fractures. Presence of prodromal pain, thickened cortex with cortical beaking may be an early clue for predicting the atypical fractures. High risk patients need periodical skeletal survey and a close follow up for early detection of cases.
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Bhadada
authors.forename: Subbiah
authors.initials: S
authors.lastname: Sridhar
authors.forename: Jeyaram
authors.initials: J
authors.lastname: Muthukrishnan
authors.forename: Ambrish
authors.initials: A
authors.lastname: Mithal
authors.forename: Dinesh C
authors.initials: DC
authors.lastname: Sharma
authors.forename: Anil
authors.initials: A
authors.lastname: Bhansali
authors.forename: Vandana
authors.initials: V
authors.lastname: Dhiman
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D019386:Alendronate; D004164:Diphosphonates / Q000009:adverse effects* / Q000627:therapeutic use*; D005260:Female; D005264:Femoral Fractures / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D006801:Humans; D007093:Imidazoles; D007194:India; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000188:drug therapy*; D062706:Prodromal Symptoms; D012189:Retrospective Studies; D000077211:Zoledronic Acid
chemical_list: D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid; D019386:Alendronate