title: Atypical femur fractures in patients receiving bisphosphonate therapy: etiology and management.
abstract: Osteoporosis is a growing problem that is projected to affect more than 50% of American adults by 2020. Bisphosphonate therapy is currently the primary mode of treating osteoporosis in this population. While bisphosphonate therapy has been successful in increasing bone mineral density, data has shown an increased risk of atypical femur fractures with prolonged therapy. Atypical femur fractures are characterized by low-energy or atraumatic injuries that occur in the subtrochanteric region. They originate on the medial cortex, travel transversely, and typically have little or no comminution. Conservative therapy is indicated for patients with incomplete fractures without prodromal symptoms. Patients with incomplete fractures and significant prodromal symptoms or visible fracture line on radiographs, those who have failed conservative management, and those with complete fractures should be treated with intramedullary nail fixation. Evaluation should involve imaging of the contralateral femur. Teriparatide therapy may be considered for patients without contraindications. While the incidence of these fractures is low, it is likely that these rates will increase with the aging population and increased prevalence of patients being treated with bisphosphonate therapy.
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, 2912 Taubman Center, SPC 5328, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Blum
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, 2912 Taubman Center, SPC 5328, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Cummings
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, 2912 Taubman Center, SPC 5328, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Goulet
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, 2912 Taubman Center, SPC 5328, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Perdue
authors.affiliation: Department of Orthopaedic Surgery, Denver Health Medical Center, Denver, CO, 80204, USA.
authors.forename: Cyril
authors.initials: C
authors.lastname: Mauffrey
authors.affiliation: Department of Orthopaedic Surgery, University of Michigan, 2912 Taubman Center, SPC 5328, 1500 E. Medical Center Dr., Ann Arbor, MI, 48109, USA. mehake7@yahoo.com.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Hake
mesh_terms: D000368:Aged; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D016723:Bone Remodeling / Q000502:physiology; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D011859:Radiography
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates
keywords: Atypical femur fracture; Bisphosphonate therapy; Osteoporosis; Stress fractures