Atypical Fractures and Long-term Bisphosphonate Use

Bisphosphonates are the most common drug therapy for osteoporotic fracture prevention, prescribed to millions of people around the world. Concern among doctors and patients has arisen following recent media reports that cite a possible association between unusual and unexpected (atypical) fractures of the upper thigh bone and bisphosphonate use.

A working group of the International Osteoporosis Foundation and the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) have published a position paper on the association between subtrochanteric femoral (upper thigh bone) fractures and long-term treatment with bisphosphonates.

The Position Paper's key messages:

  • Atypical fractures in association with bisphosphonate use are rare, estimated at one per 1,000 patients per year.
  • Small clinical case reports and reviews have reported increased risk of these fractures among bisphosphonate users, but a large register-based study and restrospective analyses of phase III trials of bisphosphonates do not show an increased risk.
  • More epidemiological research and well-designed studies are needed to clearly define and characterize atypical fractures and to learn about other risk factors in patients who have suffered these fractures.
  • Available evidence shows the well-known benefits of bisphosphonate treatment far outweigh the relatively low risk of these rare, atypical fractures. For every 10,000 high-risk patients undergoing bisphosphonate treatment, approximately 100 hip fractures and 750 fractures at other sites are prevented, whereas only 3 to 6 atypical fractures could be expected.
  • Patients should discuss any concerns with their doctors. Doctors should, as with all drug treatments, advise patients of any potential side effects or risks. Patients with pain in the hips, thighs or femur should be radiologically assessed, and examined for possible atypical subtrochanteric fracture. The radiographic changes should be examined for orthopaedic intervention or close monitoring. The decision regarding therapy should be based on an individual benefit-risk assessment.

Download the position paper Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinicaland Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report