Prolonged
bisphosphonate use has been associated with increased risk of atypical
femoral fractures. Very few cases of atypical
femoral fractures have been reported with
denosumab. We report a case of bilateral tibial stress reactions in a 60-year-old man with no history of
osteoporosis who was on prolonged high-dose
denosumab for the treatment of
giant cell tumor of bone. He presented with a 3-month history of
pain in his bilateral shins worsening with activity and improving with rest. Although initial radiographs were unremarkable, he was found to have changes consistent with a stress reaction on magnetic resonance imaging of the distal tibia. To our knowledge, bilateral tibial stress reactions have not been previously reported with anti-resorptive
therapies (neither
bisphosphonates nor
denosumab). Our case is intriguing in terms of the development of stress reactions as a precursor to
stress fractures which may also relate to atypical fractures. Our case suggests a possible association between
denosumab use and stress reactions. Of note the indication for
denosumab in our case was for the treatment of
giant cell tumor of bone where the Food and Drug Administration (FDA) approved dose is substantially higher than the FDA approved dose for
osteoporosis treatment. Although rare, clinicians should consider the possibility of
stress fractures in patients on anti-resorptive medications such as
denosumab, especially when a patient presents with new onset thigh
pain, hip
pain or
pain over an area affecting the long bones. Evaluation by imaging of affected areas should be pursued to enable early detection and intervention, as well as prevention of morbidity and associated ongoing risk to the patient.