[What do we know about atypical fractures in patients on biphosphonates treatment? A literature review using a case series]

Aim: Retrospective review of long term biphosphonates treated patients who sustained a subtrochanteric or diaphyseal femoral fracture with an atypical pattern. A literature review is presented as an update of the topic.

Material and methods: A retrospective study was conducted on 13 subtrochanteric or diaphyseal fractures in female patients treated with biphosphonates at our institution from September 2007 to March 2011.

Results: Four cases of subtrochanteric fractures and 13 diaphyseal fractures were detected. Four patients had bilateral fractures. All cases but one (that affected only the lateral cortex) were complete fractures. Surgically, these kinds of fractures are demanding due to the hardness of the bones.

Discussion: It is difficult to know if there is any relationship between bisphosphonates treatment and atypical femoral fractures. Nevertheless, current literature supports a greater benefit of their use in preventing vertebral and non-vertebral fractures. For this reason, biphosphonates continue being considered as a first choice in the prevention of osteoporotic fractures.

Conclusions: Patients on long-term treatment with bisphosphonates may present atypical femoral fractures as a complication. It is considered that the maximum period for biphosphonates treatment should not exceed 5 years.