title: Ulnar fractures with bisphosphonate therapy: a systematic review of published case reports.
abstract: CONCLUSIONS
  A systematic review of eight ulnar fractures in seven patients with bisphosphonate therapy was performed to describe the characteristics and predisposing factors. The proximal ulna is likely to be fractured, especially in the dominant limb of elderly female patients using walking aids after 7 to 15 years of bisphosphonate use.
  
  
  BACKGROUND
  Long-term bisphosphonate use has been suggested to result in decreased bone remodelling and increased risk of atypical fractures. While the relationship between bisphosphonate use and atypical femoral fractures has been extensively studied, there is relative rarity and unawareness of these fractures in the forearm. We conducted a systematic review of existing case reports to better describe the characteristics and predisposing factors for fractures occurring in patients with bisphosphonate therapy.
  
  
  METHODS
  The systematic review was conducted according to PRISMA guidelines. All studies with ulnar fractures in individuals with history of bisphosphonate use were included, with data extracted and analysed in totality.
  
  
  RESULTS
  Seven patients with eight fractures are included. Predisposing factors include elderly females requiring walking aids. There is a propensity for the proximal ulna to be fractured, especially in the dominant limb used for ambulation or transfer. All patients were on bisphosphonate for 7 to 15 years. All fractures were atraumatic, non-comminuted, transverse in configuration, had localised periosteal or endosteal thickening at the fracture site and generalised cortical thickening of the diaphysis.
  
  
  CONCLUSIONS
  Ulnar fractures in patients with bisphosphonate therapy demonstrate features similar to those described for atypical femoral fractures, suggesting that these fractures could also possibly be due to bisphosphonate use. However, the ulna appears to be able to tolerate longer periods of alendronate use prior to fracture development. The mechanism and characteristics of these fractures additionally suggest the presence of repetitive stress that accumulates over time due to suppressed bone remodelling in patients on bisphosphonates, eventually resulting in these fractures.
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore (NUS), 1E Kent Ridge Road, NUHS Tower Block, Level 11, Yong Loo Lin School of Medicine Dean's Office, Singapore, 119228, Singapore, sharontansiheng@gmail.com.
authors.forename: S H S
authors.initials: SH
authors.lastname: Tan
authors.forename: S
authors.initials: S
authors.lastname: Saseendar
authors.forename: B H M
authors.initials: BH
authors.lastname: Tan
authors.forename: A
authors.initials: A
authors.lastname: Pawaskar
authors.forename: V P
authors.initials: VP
authors.lastname: Kumar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D004164:Diphosphonates / Q000009:adverse effects*; D005260:Female; D015775:Fractures, Stress / Q000139:chemically induced*; D006801:Humans; D010024:Osteoporosis / Q000188:drug therapy*; D012307:Risk Factors; D012656:Self-Help Devices / Q000009:adverse effects*; D013997:Time Factors; D016896:Treatment Outcome; D014458:Ulna Fractures / Q000139:chemically induced*; D016138:Walking
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates