Measurement of proximal femoral morphology and analysis of 500 cases in Hunan Province

Abstract

To evaluate the effect of age and gender on the femoral morphology to guide prosthesis selection in operation and design. A total of 500 females and males were collected from the departments of orthopedics and medical radiology, Second Xiangya Hospital, Central South University. Informed consent was obtained from all subjects. All patients underwent anteroposterior position scan of the left or right hip joint using Philips Digital Diagnost DR system. The shooting range included the hip joint and at least 2/3 of the proximal femur. The images were measured with Onis 2.3 software. We measured 13 parameters from the patients, including the external parameters of the femur, radius-length parameters of femoral medullary cavity, and morphological parameters of the femoral medullary cavity. Compared with Westeners, the offset was smaller, while the neck shaft angle was significantly larger in Chinese population (P<0.05). Most parameters of the proximal femoral medullary cavity diameter were significantly smaller in Chinese population than those in Westerners (P<0.05). The canal flare index in Chinese population was significantly larger than that in the Westerners (P<0.01). According to the Noble classification, in Chinese population, the proportion of champagne flute type was significantly larger, while the proportion of standard type was significantly smaller than that in Westerners. There was significant difference in the proximal femur between Chinese population and Westerners. The largest difference of the proximal morphology was presented between males and females in the 31-50 years old people (P<0.05), while the smallest was in the over 70 years old population (P>0.05). The main differences between 31 and 70 years old were the diameter of femoral head, the offset of isthmus, the medullary cavity diameter and extracortical width at isthmus level and the medullary cavity diameter at the level of the lesser trochanter (P<0.05). The modullary transverse diameter at 20 mm below the lesser trochanter and isthmus and extracortical width of isthmus in the male and female group was positively correlated with age (P<0.01), while the parameters of the proximal femoral canal morphology in the female group were negatively correlated with age. The female canal parameters had a stronger correlation. Chinese proximal femoral parameters are significantly different from Westerners. When people, especially females, get older, the medullary cavity diameter of the isthmus and proximal femur becomes wider and the morphology of the femur becomes straight. The difference in the femoral morphology between the male and female decline with the age. There is almost no difference for the over 70 years old. For the 31-70 years old, The male femoral cavity diameter is larger and the position of isthmus is lower than in the females.