In the periosteal dissector group , there were 47 males and 63 females , with an average age of ( 58.8 + / - 17.2 ) years old ; the degree of genuavarus was ( 14.0 + / - 3.5 ) degrees ; the weight was ( 65.6 + / - 12.8 ) kg ; the body mass index ( BMI ) was ( 26.6 + / - 3.6 ) kg/m2 .