Knee pain on the bike but not on the roller? Why is that? - Where does plica syndrome on the knee come from?

Question from TOUR reader Florian B.: After two intensive months of cycling, I had pain when bending my knee after a tour and was told by a specialist that I was suffering from plica syndrome, but that it should be cured in a few weeks. After a break of almost three weeks, I carefully trained on my roller for a week. After four two-hour roller training sessions, there were no problems at all, which is why I dared to go out again. But after just 15 minutes I felt my knee and turned round. A few hours later, I cycled on the roller for an hour and a half at a higher intensity than outside - again without any discomfort. On the road I was wearing different shoes, but both pairs have fresh cleats, so I would rule that out as a problem. Could it be that the long tight trousers outside are pressing on the knee when pedalling and causing pain?

Answer from Dr Christian Merkl: Plica syndrome is rather rare and hardly ever occurs in my patients. According to your description, the transmission of force between the kneecap and the femoral condyle is disturbed. The so-called anterior extensor apparatus is essentially determined by ligaments and their attachments, cartilage structures and synovial fluid. Disorders occur in the so-called femoropatellar gliding bearing of the knee joint - i.e. between the kneecap and the thigh bone - if these structures are less resilient.

The main reasons for this are excessive strain - often in winter in combination with cold weather. If there is insufficient regeneration (12 hours for energy, 36 hours for muscles, up to 10 days for ligaments/cartilage!), this leads to reduced resilience with pain due to "soft cartilage" or inflamed ligament attachments.

An incorrect seat position - this may be due to a different crank length or the rotation of the cleat - leads more quickly to overloading and reduced resilience due to pain.

When I was still accompanying the Tour of Bavaria as a race doctor, I saw these problems in professionals who had knee joint problems after a few kilometres following a bike change due to a defect, which then affected the entire Tour.

The way I see your problem from a distance, it must be a position problem, as plica syndrome would always be noticeable - regardless of whether you train indoors or outdoors.