A common overuse injury generally affecting children aged 9-16 resulting in inflammation and sometimes tearing of ligaments within the knee and lower leg. Osgood–Schlatter disease often coincides with growth spurts.

• Chronic, repetitive stress to the attachment of the patellar tendon (the tendon between the knee bone and shin bone) on the bony outgrowth at the top of the shin bone.
• Sports involving repeated knee bending and jumping can create this stress.
• The growth zone (epiphyseal plate) may be damaged and separate from the surrounding bone.
• Risk factors may include over weight and over conditioning (running and jumping).

• Local pain, inflammation, swelling and tenderness just below the kneecap
• Calcification of the patellar tendon, creating painful, visible lumps just below the knee. Calcification is visible on x-ray.
• Knee pain that is aggravated by activity and improved with rest
• Tightness of the surrounding muscles, especially the thigh muscles (quadriceps)

Some people experience mild pain with certain activities, especially running and jumping, while other may have constant, severe pain.

Rest, ice and anti-inflammatory medications will help relieve symptoms.

The condition usually heals after rest and particularly after bone growth is finished, but activity may need to be limited for several months. Permament damage may result if activity is not reduced.