Teriparatide Prevented Near Atypical Femur Fracture by Reducing Cortical Thickening in a Symptomatic Patient With Prolonged Use of Oral Bisphosphonate: A Case Report

Long-term bisphosphonate (BP) treatment is associated with adverse event of atypical femur fracture (AFF) due to their long-lasting unique bone-seeking properties, and subsequent uptake by osteoclasts results in sustained inhibition of bone resorption even after their cessation. We report a case of postmenopausal women who presented with pain and severe femoral cortical thickening on alendronate for 10 years, but with no signs of obvious radiolucent fracture line on radiograph and bone marrow edema on magnetic resonance imaging representing impending AFF. Teriparatide (TPP) was started after discontinuation of BP which showed resolution of pain and reduction of femoral cortical thickness. We recommend biannual radiographs follow-up for evaluation of cortical thickening in patients taking BP along with the review of bone mineral density, and consideration of treatment with TPP if cortical thickening is present.