17 June 2025
: Case report 
Twenty Years of Continuous Bisphosphonate Use Leading to Atypical Bilateral Femoral Fractures: A Case Report
Unusual clinical course, Challenging differential diagnosis, Diagnostic / therapeutic accidents, Adverse events of drug therapy, Clinical situation which can not be reproduced for ethical reasons
Anna Maria Monachino ABDEF 1*, Massimo Berdini
ABDEFG 2, Valerio Tiburzi E 1,2, Roberto Procaccini AB 2, Antonio Pompilio Gigante A 1
DOI: 10.12659/AJCR.946435
Am J Case Rep 2025; 26:e946435
Table 1 2010–2013 ASBMR Task Force case definition of atypical femoral fractures.
| Fracture line located anywhere along the femur shaft from just distal to the lesser trochanter to just proximal to the supracondylar flare |
| Fracture associated with no trauma or minimal trauma, as in a fall from standing height or less |
| Transverse or short oblique configuration [] |
| Non-comminuted fracture [or minimally comminuted ASBMR2013] |
| Complete fractures extend through both cortices and may be associated with a medial spike; incomplete fractures involve only the lateral cortex [] |
| Localized periosteal reaction of the lateral cortex |
| Generalized increase in cortical thickness of the diaphysis |
| Prodromal symptoms such as dull or aching pain in the groin or thigh |
| Bilateral fractures and symptoms |
| Delayed healing [] |
| Comorbid conditions (eg, vitamin D deficiency, rheumatoid arthritis, hypophosphatasia) |
| Use of pharmaceutical agents (eg, bisphosphonates, glucocorticoids, proton-pump inhibitors) |
| Fractures of the femoral neck |
| Intertrochanteric fractures with spiral subtrochanteric extension |
| Pathological fractures of the femur associated with primary or metastatic bone tumors |
| Peri-prosthetic fractures of the femur |
| All major features are required for diagnosis of atypical femoral fractures. None of the minor features are required for diagnosis, but have sometimes been associated with these fractures. Changes made since the ASBMR revised the criteria in 2013 are shown in italics []. |