Abstract
PURPOSE OF THE STUDY
To assess if prolonged use of Bisphosphonates in Osteogenesis Imperfecta alters the pattern of femoral fractures.
Osteogenesis Imperfecta (OI) has been treated with Bisphosphonates for many years with some clear clinical benefits. In adult cohorts there are reports of a new pattern of atraumatic subtrochanteric fractures seen with Bisphosphonate treatment.
SUMMARY OF METHODS
This study assesses the location of femoral fractures in a cohort of 176 OI patients treated with Bisphosphonates over a two year period and compares it to a historical control group of 45 managed prior to the advent of this specific treatment.
SUMMARY OF RESULTS
review of the radiological digital archive identified 16 femoral fractures in this time period in the Bisphosphonate treated group. All but 2 were within 5cm of the lesser trochanter, and 50% within 3cm. In comparison, the historical group, composed of 26 femoral fractures had a more widespread fracture pattern with the most frequent location being the mid-diaphysis. Many of the sub-trochanteric fractures in the treatment group occurred with minimal trauma, and in some cases without any injury.
CONCLUSION
It appears that concerns in the adult osteoporotic population treated with Bisphosphonates are mirrored in Osteogenesis Imperfecta. It is possible that the high bending moments in the proximal femur together with altered mechanical properties of cortical bone secondary to the use of this group of drugs, mediated by abnormal osteoclast and osteoblast function, increase the risk of this type of injury and warrants further investigation.
