Bisphosphonate therapy associated with bilateral atypical femoral fracture and delayed union

Abstract

Objectives: The aim of this study was to identify the risk factors for developing atypical femoral fractures (AFF) and to examine the effect of bisphosphonate (BP) therapy on delayed bone union and bilateral fractures. Patients and methods: Between January 1st, 2012 and December 31st, 2020, a total of 74 AFF patients (8 males, 66 females; mean age: 75.4±7.2 years; range, 51 to 94 years) were recorded in two centers and retrospectively analyzed. A control fragility fracture group (n=143) was compared to the AFF group according to fracture characteristics, surgical fixation methods, comorbidities, and medications. The AFF patients were selected and subdivided according to their BP therapy: Group 1 (without BP) and Group 2 (with BP). Group 2 was further classified into Group 2a (5 years of BP). Results: The multivariate logistic regression model showed that, BP drug use was the most significant risk factor in development of AFF (p5 years) showed longer delayed bone union, which was not significant. There was a relatively high risk of developing AFFs and bilateral fractures on BP therapy. In case of an AFF, a contralateral femoral X-ray must be always performed for signs of an impending fracture.