Atypical femoral fractures in Italy: a retrospective analysis in a large urban emergency department during a 7-year period (2007–2013)

Abstract

The aim of this study was to determine the incidence of atypical femoral fractures (AFFs) seen in a large emergency department in Italy. It was a retrospective study of all men and women aged 40 years or older admitted to the Emergency Department of Parma University Hospital for a femoral fracture. Cases were identified in the hospital database with use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 820 or 821 or text strings. All the radiographic images of fractures not clearly identified as proximal or condylar were retrieved and evaluated by three independent reviewers. Fractures were considered as atypical if all three reviewers agreed on at least four of five major features defined by the 2013 American Society for Bone and Mineral Research criteria. In the 7-year period (2007-2013), with a total follow-up of 1,383,154 patient-years, we found 22 AFFs in 21 patients, accounting for 7.1% of low-trauma subtrochanteric/femoral shaft fractures and 0.6% of all femoral fractures. The incidence was very low (1.6 in 100,000 patient-years in both sexes combined). In contrast, the incidence of classic fractures of the proximal end of the femur was at least two orders of magnitude higher (typical/atypical rate ratio 152). Bisphosphonate use was reported in 13 patients (62%; mean treatment duration 9 years; range 5-14 years). Among 286 patients with typical subtrochanteric/femoral shaft fractures, 20 were being treated with bisphosphonate (7%; odds ratio 22; 95% confidence interval 8-58; p < 0.001). This study confirms the very low incidence of AFFs in the largest Italian cohort of patients to date. Even though the risk is higher in patients treated with bisphosphonates, AFFs are very rare, and typical femoral fractures are at least 100-fold more frequent.

Prevalence and risk factors for atypical femoral fracture among Lebanese patients with hip and shaft fractures

“…This is still in accordance with other studies, where AFF patients are significantly younger than their non-AFF counterpart. 10 , 13 , 14 , 17 , 18 However, studies based in South Korea showed a slightly lower mean age of AFF patients, ranging between 71.1 and 71.4 yr, when compared to other studies, including ours (72 to 74 yr), potentially underlining the higher risk of AFFs in Asian populations.…”

“…This is similar to a study conducted in Italy, where 62% of AFF patients were previously exposed to BP. 10 Interestingly, exposure to BP in the AFF population was smaller when compared with 3 other large US and European population-based studies in which 90.5%, 78%, and 69% of AFF patients had evidence of previous BP or Dmab use and a smaller UK study where 70% of AFF patients were previously exposed to BP. 16 , 17 , 22 , 24 However, 3 smaller studies in South Korea and Thailand found a smaller proportion of AFF patients, ranging from 35.3% to 44.4%, with previous exposure to BPs.…”

“…The prevalence of AFFs in our study is nearly double that seen in Italy (0.6%), the only identified Mediterranean country where AFF prevalence was studied. 10 Methodologies between the 2 studies were similar, both had a similar population of adults aged 40 and above admitted for a hip and shaft fracture at a single center. The difference in the prevalence of AFF could be accounted for by different baseline risk factors between ethnic groups and other risk factors such as a higher prevalence of vitamin D deficiency in the Lebanese population.…”

Untitled

“…The patient in this study presented full radiographic consolidation after a mean of 6.8 months, similar to the time of 7.3 months found in the literature [10]. It is important to note the tendency of these fractures to develop delay in consolidation and pseudoarthrosis in up to 50% of cases [13][14][15].…”