title: Bisphosphonates and atypical subtrochanteric fractures of the femur.
abstract: OBJECTIVE
  Bisphosphonates are widely used as first-line treatment for primary and secondary prevention of fragility fractures. Whilst they have proved effective in this role, there is growing concern over their long-term use, with much evidence linking bisphosphonate-related suppression of bone remodelling to an increased risk of atypical subtrochanteric fractures of the femur (AFFs). The objective of this article is to review this evidence, while presenting the current available strategies for the management of AFFs.
  
  
  METHODS
  We present an evaluation of current literature relating to the pathogenesis and treatment of AFFs in the context of bisphosphonate use.
  
  
  RESULTS
  Six broad themes relating to the pathogenesis and management of bisphosphonate-related AFFs are presented. The key themes in fracture pathogenesis are: bone microdamage accumulation; altered bone mineralisation and altered collagen formation. The key themes in fracture management are: medical therapy and surgical therapy. In addition, primary prevention strategies for AFFs are discussed.
  
  
  CONCLUSIONS
  This article presents current knowledge about the relationship between bisphosphonates and the development of AFFs, and highlights key areas for future research. In particular, studies aimed at identifying at-risk subpopulations and organising surveillance for those on long-term therapy will be crucial in both increasing our understanding of the condition, and improving population outcomes.Cite this article:N. Kharwadkar, B. Mayne, J. E. Lawrence, V. Khanduja. Bisphosphonates and atypical subtrochanteric fractures of the femur.Bone Joint Res2017;6:144-153. DOI: 10.1302/2046-3758.63.BJR-2016-0125.R1.
authors.affiliation: The Heart of England NHS Foundation Trust, Bordesley Green East, Birmingham B9 5SS, UK.
authors.forename: N
authors.initials: N
authors.lastname: Kharwadkar
authors.affiliation: F2, James Cook University Hospital, Marton Rd, Middlesbrough TS4 3BW, UK.
authors.forename: B
authors.initials: B
authors.lastname: Mayne
authors.affiliation: Junior Clinical Fellow, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0QQ, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Lawrence
authors.affiliation: Department of Trauma and Orthopaedics, Addenbrooke's Hospital, Box 37, Hills Road, Cambridge CB2 0QQ, UK vk279@cam.ac.uk.
authors.forename: V
authors.initials: V
authors.lastname: Khanduja
keywords: Atypical fractures of the femur; Bisphosphonates; Bone remodelling; Femoral geometry