In recent years, the incidence of proximal femur fractures has been increasing with the aging of the population. There has been a growing number of those patients who injure on the other side of the hip at later date. We studied the relationship between proximal femurfractures and knee osteoarthritis, which is one of the diseases preceding fractures.
  We surveyed 234 and 17 patients hospitalized with unilateral and bilateral fractures, respectively at Atsumi Hoapital from April 2008 to March 2011. The research covered sex, age, the cause of injury, the period until they had proximal femur fractures on the other side, bilateral-fracture rate, incidence rates of diseases (cerebrovascular, eye and respiratory), knee osteoarthritis, dementia, diabetes and other forms of fracture.
  As a result, we confirmed the connection between knee osteoarthritis and bilateral fractures. There was every indication that knee osteoarthritis may be a major factor which leads to bilateral fractures. All patients with bilateral fracture injured resulting from falls.
  We believe it is important to take an approach on the treatment of hip fractures and prevention of knee osteoarthritis and falling.