Munugoda IP, et al. - Herein, the authors assessed the relationship between ambulatory activity (AA), body composition measures and hip or knee joint replacement (JR) due to osteoarthritis. Experts noted that an objective measure of AA was associated with a small elevated risk of knee replacement (KR) and a small reduced risk of hip replacement (HR). They found the worse body composition profiles to be related to the knee replacement, but not with the hip replacement. With regard to habitual activity and obesity, different causal pathways for each site could be suggested.