Abstract
Introduction
The emergence of a new variant of subtrochanteric stress fractures of the femur affecting patients on oral bisphosphonate therapy has only recently been described. This fracture is often preceded by pain and distinctive radiographic changes, and associated with a characteristic fracture pattern. We undertook a review of this cohort of patients in our service.
Method
A retrospective review was carried out looking for patients with subtrochanteric fractures who were taking oral bisphosphonates presenting with a low velocity injury over a two year period. Clinical data and radiographs were assessed.
Results
11 fractures were found in 10 patients matching the inclusion criteria outlined. All were female, and taking bisphosphonates for a mean of 4.3 years. 5 of the 10 patients described prodromal symptoms, for an average of 7.8 months before fracture. Although all fractures were deemed low velocity, 5 of 11 were atraumatic. 3 patients have had bilateral subtrochanteric fractures. Presence of the distinctive radiological ‘bleb’ was common. Surveillance on 2 patients shows lateral cortical blebs on the contralateral femur which merit close follow up.
Conclusion
Patients taking oral bisphosphonate therapy may be at risk of a new variant of stress fracture of the proximal femur. Awareness of the symptoms is key to ensure appropriate investigations are undertaken. Following such a fracture surveillance of the contralateral femur is recommended, and the option of discontinuing bisphosphonates should be discussed.
