Atypical subtrochanteric fractures in Korean hip fracture study.

ABSTRACT

In Korean, atypical subtrochanteric fractures (ASF) were rare. Higher BMI and use of bisphosphonate were significant risk factors of ASF. INTRODUCTION: Recently, ASF have been reported to increase among patients on bisphosphonate. However, the incidence of ASF and the association between ASF and bisphosphonate use have not been well defined in Asian population. Our purposes are (1) to estimate the proportion of ASF among Korean patients with proximal femur fracture and (2) to determine the associated risk factors of ASF in the Korean patients. METHODS: We conducted a multicenter (16 academic hospitals), prospective Korean hip fracture study on hip fracture in a cohort of patients aged 50 years or older from South Korea between July 2014 and May 2016. As a part of Korean hip fracture study, primary analysis examined the proportion of ASF among proximal femur fracture. To identify ASF, according to the definition by ASBMR task force, all radiographs of subtrochanteric fracture were reviewed. Associated risk factors for occurrence of ASF were also evaluated by using multivariable logistic regression analysis. RESULTS: Among 1361 patients with proximal femoral fractures due to low-energy trauma, 17 fractures (1.2%) were identified as ASF. Higher BMI and use of bisphosphonate before injury were independent risk factors of ASF. CONCLUSION: In Korean, ASF were rare. Higher BMI and use of bisphosphonate were significant risk factors of ASF.