Scientists have discovered that a small bone in the human knee that they had previously thought was disappearing as we evolve seems to be sticking around.
They believe that this bone – the fabella – could be the source of knee pain in some people.
Many people don’t have a fabella and live perfectly well without one. Doctors don’t believe it serves a purpose for those that do have one.
It is located in the tendon beneath the knee.
A team at from Imperial College London led by Dr Michael Berthaume has studied medical literature on knees from the last 150 years around the world.
Reports of the fabella in these reports increased three-fold between 1918 and 2018. In 1918 a fabella was thought to be present in around 11% of people, while that figure has increased to 39% today.
Dr Berthaume said: “The fabella may behave like other sesamoid bones to help reduce friction within tendons, redirecting muscle forces, or, as in the case of the kneecap, increasing the mechanical force of that muscle. Or it could be doing nothing at all.”
Experts say the bone could be causing us problems as studies show that people suffering from osteoarthritis of the knee are twice as likely to have one.
It also causes discomfort in some people and adds complications to knee replacement surgery operations.
We don’t know why the fabella is making a comeback, but experts believe it could be due to our modern nutrition.
We have become taller and heavier and our shinbones and calf muscles have become longer, all of which puts the knee under more pressure.
The fabella grows in response to the level of force placed upon it and movements it needs to make.
Discovering why the bone has made a comeback could help doctors treat patients with knee problems.
The team say the next step is to look into demographics and see whether any patterns emerge that would suggest people of a certain age, gender or location are more likely than others to have a fabella.