People report anterior knee pain, often with an aching quality. The symptom onset is insidious. Rarely is a discrete injury described. Usually, the problem is below the kneecap but it may also be above. Jumper's knee can be classified into 1 of 4 stages, as follows: Stage 1 – Pain only after activity, without functional impairment Stage 2 – Pain during and after activity, although the person is still able to perform satisfactorily in his or her sport Stage 3 – Prolonged pain during and after activity, with increasing difficulty in performing at a satisfactory level Stage 4 – Complete tendon tear requiring surgical repair It begins as inflammation in the<unk>  tendon where it attaches to the<unk> and may progress by tearing or degenerating the tendon. People present with an ache over the<unk> tendon. Most people are between 10 and 16 years old. Magnetic resonance imaging can reveal edema (increased T2 signal intensity) in the proximal aspect of the<unk>  tendon.
Patellar tendinitis
Osgood–Schlatter disease
Pes anserine bursitis
Chondromalacia patellae
Prepatellar bursitis
Patellofemoral pain syndrome
Infrapatellar bursitis
Ischial bursitis