Osteoarthritis (OA) is an age-related disease. However, ageing and OA are independent processes. In older individuals, factors related to normal ageing (for example, stem cell exhaustion) converge with OA risk factors (for example, genetic factors or obesity) leading to joint tissue deterioration and painful disease. Osteoarthritis involves damage to both cartilage (smooth elastic joint tissue) and the underlying bone. In older people, continued mechanical forces applied to the joints, which may be exacerbated by obesity, lead to cell death in these tissues. Stem cells supply new healthy cells to these tissues, and are termed mesenchymal stem cells (MSCs). In this talk, Dr Elena Jones will present research which shows that the numbers and function of joint-resident MSCs decline with healthy ageing. Furthermore, in OA tissues MSCs gain additional properties which make new bone thicker, but weaker. This has an impact on the overlaying cartilage that becomes exposed to harsher mechanical forces. We will discuss our strategy to modulate MSCs to slow down their ageing and restore their functionality in OA-damaged joints.