Articular cartilage is a deformable tissue which promotes proper function of diarthroidal joints by providing a low-friction wear-resistant layer on the end of each bone. Over many years, the cartilage in weight-bearing joints such as the knees and hips can thin and degrade, leading to a loss of mobility and function. This condition, termed osteoarthritis, is responsible for billions of dollars in lost labour and millions of joint replacements annually. While cartilage can at least partially self-repair, the absence of a blood supply lengthens the characteristic times of repair processes to months or even years, rendering some people's activity patterns unsustainable in the long run. We will see how techniques from the powerful engineering discipline of reliability theory can be adapted to study biological systems, and in particular to analyse models of long-term cartilage turnover across a wide variety of lifestyles.

osteoarthritis; cartilage; reliability theory; bioengineering