Tendonitis of the patella tendon is a common sports medicine problem.
It is caused by overuse and treatment includes rest, physiotherapy and PRP (Platelet Rich Plasma) injection into the damaged tendon. Surgery is seldom indicated.
It is very important that the physiotherapist give eccentric knee tendon exercises.
Cyclists with this problem, need to give attention to their bike setup. Generally higher saddles with a more straight knee gives better function.