Data from all people enroled onto the US Osteoarthritis Initiative programme who had undergone a THA (n = 104) or TKA (n = 165), within a 12-month period, were compared to those who had not undergone an arthroplasty (n = 4631). Data were collected on: the number of participants who reported a fall within a 12-month period; the frequency of falls in this period; and whether a fracture was sustained during this period