Introduction: This study aimed to determine ethnic differences in the proximal femur morphology of elderly patients with femoral neck fractures in Singapore.
Methods: 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.
Results: 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).
Conclusion: 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.
Keywords: Dorr classification; Singapore population; femur head size; morphology; proximal femur.