Background Studies have identified the relationship between the menopause and femoral neck fracture risk. Recent research has implicated proximal femoral shape, measured using Hip Structural Analysis (HSA), in femoral neck fracture risk. It is not known if detrimental changes of proximal femur shape during the menopause confound reduction of bone mineral density, thus increasing femoral neck fracture risk.
Objectives This study aims to investigate the influence of menopause upon proximal femur shape.
Methods Data of pre and post-menopausal women attending for a DXA scan in a UK district general hospital between 2006 and 2010 were identified. Logistic regression analysis was used to compare HSA measurements, femoral neck t-score and previous low-trauma femoral neck fracture status between the pre and post-menopausal women; unadjusted then adjusted for possible confounders: age, body mass index (BMI). The following data were recorded: age, body mass index (BMI), previous low-trauma femoral neck fracture status, femoral neck t-score, all HSA measurements were collated: distance from centre of femoral head to centre of femoral neck (d1), distance from centre of femoral head to inter-trochanteric line (d2), mean femoral neck diameter (d3), distance from centre of mass of femoral neck to superior neck margin (y), hip axis length (HAL), cross-sectional moment of inertia (CSMI) and proximal femur strength index (SI). HSA measurements of individuals that had sustained a femoral neck fracture were taken from the contra-lateral hip.
Results Compared to the pre-menopausal group (n=630), the post-menopausal (n=9372) group had a significantly higher mean age: 37.10 years (SD 0.26) vs 66.58 years (SD 0.10), a significantly higher mean BMI: 25.54 kg/m2 (SD 0.25) vs 26.79 kg/m2 (SD 0.05), a significantly lower mean femoral neck t-score: -0.34 (SD 0.04) vs -1.29 (SD 0.01) and a significantly higher proportion of individuals with a previous femoral neck fracture: 0.95% vs 3.10%, respectively.
Logistic regression modelling, adjusted for age and BMI, indicated that post-menopausal status was significantly associated with a previous femoral neck fracture and a lower femoral neck t-score; no HSA measurement significantly differed between the pre and post-menopausal groups.
Conclusions This study indicates that proximal femur shape is not implicated in the association between post-menopausal status and increased femoral neck fracture risk when age and BMI are taken into consideration. This study indicates that the reduction of BMD associated with the menopause is the most influential factor in femoral neck fracture risk.
Disclosure of Interest None Declared