In the electric scalpel group , there were 49 males and 61 females , with an average age of ( 59.6 + / - 16.7 ) years old ; the degree of genuavarus was ( 15.0 + / - 4.7 ) degrees ; the weight was ( 66.4 + / - 13.4 ) kg ; the BMI was ( 27.4 + / - 4.1 ) kg/m2 .