Radiographic study of the proximal femur morphology of elderly patients with femoral neck fractures: is there a difference among ethnic groups?

This study aimed to determine ethnic differences in the proximal femur morphology of elderly patients with femoral neck fractures in Singapore. We reviewed the medical records of 101 men and 288 women aged 60-109 (mean 76.4) years who underwent hip hemiarthroplasty for femoral neck fractures between 1 June 2010 and 31 December 2015. Patients' age, gender and race were recorded. Plain anteroposterior radiography was used to measure the following: calcar width to canal width ratio of the ipsilateral femur; neck-shaft angle; hip offset; neck length; and neck width of the contralateral proximal femur. Chinese women had slightly larger femoral heads (mean 43.88 mm) as compared to Malay (mean 42.92 mm, p = 0.044) and Indian (mean 42.34 mm, p = 0.025) women. Chinese women also had a significantly lower mean calcar-to-canal width ratio (0.606) as compared to Malay (0.664, p = 0.002) and Indian (0.693, p = 0.004) women. The mean neck-shaft angle of Chinese women was significantly greater than that of Indian women (137.48° vs. 127.00°, p = 0.001). We found statistically significant differences in the femoral head sizes and calcar-to-canal width ratios among women of different ethnic groups. There were also differences in neck-shaft angles between Chinese and Indian women, and between Malay and Indian women.