Background: The incidence of fragility hip fractures, intracapsular and extracapsular, has been increasing worldwide. Fracture stability is important for treatment decision-making and is related to the expected rate of complications. It is unclear whether metabolic therapy explains the increased incidence of unstable fractures.

Objectives: To investigate the possible association between treatment with bisphosphonates and the various patterns encountered with intertrochanteric hip fractures.

Methods: Patients with fragility hip fractures who were treated in our department between 2013 and 2014 were included in this study. They were classified into three groups: group 1 had a stable extracapsular fracture, group 2 had an unstable extracapsular fracture, and group 3 had an intracapsular fracture. Collated data included: osteoporosis preventive therapy and duration, fracture-type, history of previous fractures, and vitamin D levels.

Results: Of 370 patients, 87 were previously treated with bisphosphonates (18.3% prior to fracture in group 1, 38.3% in group 2, and 13.8% in group 3). Of those treated with bisphosphonates, 56.3% had an unstable fracture, 21.8% had a stable fracture, and the rest an intracapsular fracture. In contrast, only 27.9% of patients who were not treated with bisphosphonates had an unstable fracture and 30.0% had stable fractures.

Conclusions: Our findings show a higher proportion of complex and unstable fractures among patients with fragility hip-fractures who were treated with bisphosphonates than among those who did not receive this treatment. The risk for complex and unstable fracture may affect the preferred surgical treatment, its complexity, length of surgery, and rehabilitation.