Osgood-Schlatter Disease

Description

Osgood-Schlatter is a common cause of knee pain in growing children, especially active ones. It is an irritation of the growth area at the top of the shin, just below the kneecap, where the kneecap tendon attaches. It is not a serious injury, and it is not caused by anything your child did wrong.

How it happens (the mechanism)

Bones grow at special zones called growth plates. The main one, the physis, is what makes a bone longer. There is a second kind, called an apophysis — a growth center at a bony bump where a tendon anchors muscle to bone. The tibial tubercle — the bump just below the kneecap, where the quadriceps (thigh muscle) attaches through the kneecap tendon — is one of these apophyses.

While a child is still growing, that apophysis is made of cartilage, not yet hardened into bone. Cartilage — the same rubbery material as in the ear or the tip of the nose — is softer than bone and weaker under tension. So when its muscle pulls hard or often, the apophysis is the part that complains.

During a growth spurt, the bones lengthen faster than the muscles can keep up, so the muscles become relatively tight and tug harder on the apophysis. Here, a tight quadriceps tugs through the kneecap tendon on the tubercle with every run, jump, and stair. Day after day, that extra, sustained tension irritates and inflames the growth center — essentially the growing child’s version of the insertional tendinitis adults get where a tendon meets bone. The pain is inflammatory and can be surprisingly sharp. (In an older teen, a single explosive effort can occasionally pull the apophysis off as an avulsion fracture; the everyday version is this inflammation.)

Symptoms

Pain and tenderness over the bony bump just below the kneecap, worse with running, jumping, kneeling, and stairs and better with rest, often with a tender, enlarged bump. One or both knees can be affected.

Doctor examination and imaging

It is usually diagnosed from the history and exam — a tender, prominent bump at the top of the shin. X-rays are not always needed, but may be taken to rule out other causes when the pain is severe, unusual, or present at rest.

Treatment

Treatment settles the irritation and, importantly, addresses its cause. Anti-inflammatory measures — ice after activity, and over-the-counter or topical anti-inflammatory medicine — give relief. But the more lasting fix is to stretch the muscle that is doing the pulling: gently lengthening the quadriceps (and hamstrings) a little each day takes tension off the apophysis and makes a real difference within a couple of weeks.

Activity is safe as tolerated — playing through manageable discomfort does not harm the knee — and a patellar tendon strap can help. Surgery is essentially never needed.

Recovery and long-term outlook

Osgood-Schlatter is self-limiting: it almost always resolves once the growth area finishes maturing, around age 14 in girls and 16 in boys. The bony bump often remains afterward but is painless.

When to call the doctor

Call if pain is severe or worsening, your child will not bear weight or use the leg at all, the area becomes very swollen, red, or warm, your child develops a fever, or things are not improving with rest as expected.

Learn more

OrthoInfo (AAOS) — Osgood-Schlatter Disease: orthoinfo.aaos.org

This information is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. For specific concerns about your child, consult a board-certified, fellowship-trained pediatric orthopaedic surgeon.