Changing pattern of femoral fractures in osteogenesis imperfecta with prolonged use of bisphosphonates

Abstract

Purpose Osteogenesis imperfecta (OI) has been treated with bisphosphonates for many years, with some clear clinical benefits. In adults, there are reports of a new pattern of atraumatic subtrochanteric fractures with bisphosphonate treatment. This study assesses if bisphosphonate treatment leads to an altered pattern of femoral fractures. Methods Retrospective review of imaging for a cohort of 176 bisphosphonate-treated OI patients to identify the locations of femoral fractures over a two-year period, as compared to a historical control group managed prebisphosphonates. Results Sixteen femoral fractures were identified in this time period in the bisphosphonate-treated group. All but two were within the subtrochanteric region. In comparison, the historical group-composed of 26 femoral fractureshad a more widespread fracture pattern, with the most frequent location being the mid-diaphysis. Many of the subtrochanteric fractures in the treatment group occurred with minimal trauma. Conclusions It appears that concerns over the treatment of the adult osteoporotic population with bisphosphonates are amplified and mirrored in OI. 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 increase the risk of this type of injury, which warrants further modification of surgical management of the femur.

Efficacy and Safety of Bisphosphonate Therapy in Children with Osteogenesis Imperfecta: A Systematic Review

“…These results are generally in line with the review of Dwan et al [39], although they included adult studies and noncontrolled studies as well. Though promising, the reduction in fracture incidence as a result of BP treatment is still not fully understood [40]. Several starting points/hypotheses can be formulated.…”

Acetabular Protrusio and Proximal Femur Fractures in Patients With Osteogenesis Imperfecta

“…A recent retrospective analysis of OI patients on bisphosphonate therapy demonstrated an increased incidence of proximal femur fractures compared with historical controls. 13 This finding raises the possibility that bisphosphonate therapy may alter the mechanical properties of bone in OI patients and consequently increase the risk for proximal femur fracture. Unfortunately, data regarding bisphosphonate use in our study population are inconsistent because of variable clinical documentation and a significant subset of our patients receiving bisphosphonate therapy at outside institutions.…”

Intramedullary Fixation Using Kirschner Wires in Children With Osteogenesis Imperfecta

“…[16][17][18] More recently, negative effects of this treatment, including delayed healing of the osteotomy site and a changing pattern of fractures, have been reported. 19,20 We have not only experienced cases that exhibited these negative effects, but also cases involving inadequate intramedullary canal formation as a consequence of bisphosphonate. We think that such cases may increase in the future, and some of them are hard to treat with elongating rods because of the narrowness of the canal.…”