Mostly due to
- people live longer than in the past and OA is a disease that becomes more common as we age
- obesity – today, lower joint OA is thought to be related to obesity (and inflammation) and genetic factors, primarily
- far greater availability of TKR today than in the past
- the period from the 1980s onward saw an increase in activities that may have increased injuries – such as jogging, tennis, basketball playing and so on, by adults, who did not do those activities as commonly as we do today.
