[Patellar tendinopathy ('jumper's knee'); a common and difficult-to-treat sports injury].

Patellar tendinopathy is a common and difficult-to-treat overuse injury of the patellar tendon with a very negative impact on the careers of many athletes. It appears to involve a failed healing process in the tendon--not inflammation--and has consequences for the treatment strategy. Rehabilitation programs are based on the principles of load reduction and an eccentric exercise program to improve muscle-tendon function and optimize the kinetic chain. Prolonged rehabilitation is necessary because of slow tendon recovery. Anti-inflammatory treatment is often unsuccessful. Surgery does not guarantee a quick symptom-free return to sport at the original level either. Extracorporeal shock wave therapy, ultrasound-guided sclerosing of new vessels and tendinous and peritendinous injections of aprotinin and autologous growth factors seem to be promising new treatment options.