Degeneration of articular cartilage places more stress on bones, and leads to reactive increased bone growth. This is the basis of wear and tear, or osteoarthritis.
For a long time, it has been known that osteoarthritis is due to more than just repetitive strain, but is influenced by factors such as diet, genetics and previous trauma.
Diet and genetics are obviously very complicated subjects that require their own articles to relate to osteoarthritis, but for the purposes of knee arthritis trauma to the medial collateral and anterior cruciate ligaments seem to be most significant. A rupture or sprain of either ligament has been linked to early onset knee osteoarthritis in many studies previously.
However, coming to light in more recent studies is the link between osteoarthritis (OA) and non-traumatic ligament damage.
A number of autopsy based studies have now shown that patients with knee OA also have very obvious wear and tear to adjacent ligaments, with the anterior cruciate being most affected. The reason for this relationship is unclear, although cadavers showing less OA also show less ligamentous damage.
It seems, therefore, reasonable to assume that protecting the ligaments of the knee from wear and tear should be the first stop on OA prevention. This sounds obvious, but until now OA prevention advice has been severely lacking.
Strengthening the hamstrings has great benefits for lower back pain, but the hamstrings also stabilise the knee and aid the anterior cruciate ligament. Performing exercises such as lunges and squats is the best way to increase hamstring strength, although correct form is paramount.
An example of research in this area: