Calcitonin Gene-Related Peptide Antagonist Use and Atypical Femur Fractures: A Case Report

JBJS Case Connect. 2025 Jul 10;15(3). doi: 10.2106/JBJS.CC.25.00148. eCollection 2025 Jul 1.

Abstract

Case: A 56-year-old woman presented with bilateral hip pain status postmechanical fall. Imaging confirmed bilateral AFFs with lateral cortical beaking. The patient was found to be on a calcitonin gene-related peptide (CGRP) antagonist, Erenumab, for treatment of recurrent migraines. CGRP is a neuropeptide and vasodilator produced by neurons in both the central and peripheral nervous system. She was treated with bilateral femoral intramedullary nails, followed by postoperative rehabilitation with physical therapy and outpatient follow-up visits.

Conclusion: Erenumab is a CGRP antagonist, which increases bone formation, and may be associated with atypical femur fractures. Further investigations are warranted.

Keywords: CGRP; atypical femur fractures; calcitonin; denosumab; migraine; osteoporosis.

Publication types

  • Case Reports

MeSH terms

  • Antibodies, Monoclonal, Humanized* / adverse effects
  • Antibodies, Monoclonal, Humanized* / therapeutic use
  • Calcitonin Gene-Related Peptide Receptor Antagonists* / adverse effects
  • Calcitonin Gene-Related Peptide* / antagonists & inhibitors
  • Female
  • Femoral Fractures* / chemically induced
  • Femoral Fractures* / diagnostic imaging
  • Femoral Fractures* / surgery
  • Fracture Fixation, Intramedullary
  • Humans
  • Middle Aged
  • Migraine Disorders / drug therapy

Substances

  • erenumab
  • Antibodies, Monoclonal, Humanized
  • Calcitonin Gene-Related Peptide Receptor Antagonists
  • Calcitonin Gene-Related Peptide