Differences in femoral fracture localizations in men and women in Switzerland between 1998 and 2021-reversal of the secular trend?

UNLABELLED: Number and age-standardized incidences of femoral fractures by sex and localization were determined annually between 1998 and 2021 in subjects aged 45 years or older living in Switzerland. The number and incidences of femoral neck, pertrochanteric, subtrochanteric, and femoral shaft fractures followed distinct unexpected trend patterns.

INTRODUCTION: Long-term incidence trends for femoral fractures by individual localizations are unknown.

METHODS: Annual absolute number of hospitalizations and median age at hospital admission between 1998 and 2021 were extracted from the medical database of the Swiss Federal Office of Statistics by sex and 10-year age groups for the following 10th International Classification of Diseases (ICD-10) codes: femoral neck (ICD-10 S72.0), pertrochanteric (S72.1), subtrochanteric (S72.2), and femoral shaft fractures (S72.3). Age-standardized incidence rates (ASI) and corresponding trends were calculated.

RESULTS: Over 24 years, the number of femoral neck fractures increased in men (+ 45%) but decreased in women (- 7%) with ASI significantly decreasing by 20% and 37% (p < 0.001 for trend for both), respectively. By contrast, the number of pertrochanteric fractures increased by 67% and 45% in men and women, respectively, corresponding to a horizontal ASI-trend in men (n.s.) and a modest significant decreasing ASI-trend in women (p < 0.001). The number of subtrochanteric fractures increased in both sexes with corresponding modest significant reductions in ASI-trends (p = 0.015 and 0.002, respectively). Femoral shaft fractures almost doubled in men (+ 71%) and doubled in women (+ 100%) with corresponding significant increases in ASI-trends (p = 0.001 and p < 0.001, respectively). Age at admission increased for all fracture localizations, more so in men than in women and more so for subtrochanteric and shaft fractures than for "typical" hip fractures.

CONCLUSION: Incidence changes of pertrochanteric fractures and femoral shaft fractures deserve increased attention, especially in men. Pooling diagnostic codes for defining hip fractures may hide differing patterns by localization and sex.