Atypical femoral fracture associated with bone-modifying agent for bone metastasis of breast cancer: A report of two cases

J Orthop Surg (Hong Kong). 2017 Sep-Dec;25(3):2309499017727916. doi: 10.1177/2309499017727916.

Abstract

Atypical femoral fractures (AFFs) are recently observed as a complication of long-term bone-modifying agent (BMA; bisphosphonate or denosumab) therapy for bone metastases. We describe the cases of two women diagnosed with breast cancer who developed incomplete AFF associated with BMAs prescribed for bone metastases. Radiographs of their femurs revealed thickening of the lateral subtrochanteric cortex, and tomosynthesis revealed a visible fracture line in the thickened cortex. They were initially treated with conservative management; however, the incomplete fracture resulted in a complete fracture. These cases highlight two major implications. First, symptomatic incomplete AFF associated with BMAs prescribed for bone metastases should be treated with surgical prophylaxis, given the fact that fracture healing is expected to require a longer duration and an incomplete fracture might potentially progress to a complete fracture during long-term conservative management. Second, tomosynthesis is useful in identifying radiolucent fracture lines that are reliable predictors of fracture propagation.

Keywords: atypical femoral fracture; bisphosphonate; bone metastasis; bone-modifying agent; denosumab; tomosynthesis.

Publication types

  • Case Reports

MeSH terms

  • Aged, 80 and over
  • Bone Density Conservation Agents / therapeutic use*
  • Bone Neoplasms / drug therapy
  • Bone Neoplasms / secondary*
  • Breast Neoplasms / pathology*
  • Denosumab / therapeutic use*
  • Diphosphonates / therapeutic use*
  • Female
  • Femoral Fractures / diagnostic imaging
  • Femoral Fractures / etiology*
  • Femoral Fractures / therapy
  • Humans
  • Middle Aged
  • Radiography

Substances

  • Bone Density Conservation Agents
  • Diphosphonates
  • Denosumab