Pain at the bump below the knee
MedlinePlus describes Osgood-Schlatter disease as a painful swelling of the bump on the upper part of the shinbone, just below the knee, called the anterior tibial tubercle. Gloucestershire Hospitals explains that this is where the large thigh muscle attaches to the lower leg bone, about 5 cm below the knee joint.
The kneecap (patella) itself is not the problem: the irritation is at the point where the patellar tendon, which continues from the thigh muscle below the kneecap, attaches to the shinbone.
Growth and pull on the tendon
MedlinePlus explains that the condition is thought to be caused by small injuries to the knee area from overuse before the knee has finished growing. The quadriceps, the large muscle at the front of the thigh, straightens the knee and is used heavily in running, jumping and climbing. When it is used a lot in sport during a growth spurt, the area where its tendon attaches becomes irritated and swollen.
Gloucestershire Hospitals says it is a childhood condition affecting growing bones around the knee, more common in boys than girls aged 10 to 15, often after a rapid growth spurt. It is linked to sports with jumping or rapid changes of direction, such as football, gymnastics, basketball, volleyball and mountain biking, and usually does not follow a specific injury.
Typical symptoms
The main symptoms described by the two sources are:
- pain, swelling and tenderness over the bump below the knee
- knee or leg pain that gets worse with running, jumping and climbing stairs
- swelling ranging from mild to severe
- limping when pain is severe
It can affect one or both knees. Gloucestershire Hospitals notes that it is a common cause of knee pain in teenagers and young adults.
Other causes and warning signs
Knee pain in young people has many causes, so the diagnosis should not be made only from age or the presence of a bump. MedlinePlus advises contacting a health care provider if a child has knee or leg pain, or if pain does not improve with treatment.
Pain after a fall or twist, a swollen, hot or red joint, fever, pain at night or at rest, or being unable to put weight on the leg are reasons for prompt medical assessment, as they point away from a simple overuse problem. Other causes of knee pain are covered in our guides on runner’s knee and inner knee pain.
Clinical assessment and x-rays
MedlinePlus says a health care provider can usually diagnose Osgood-Schlatter disease with a physical exam. A bone x-ray may be normal or may show swelling or damage at the tibial tubercle. X-rays are rarely needed unless the provider wants to check for other causes of the pain.
Gloucestershire Hospitals similarly says an x-ray is not always required but may be taken to confirm the diagnosis. Imaging is chosen by the clinician according to the examination, not done routinely.
Adjusting sport and school activities
Both sources describe adjusting activity rather than stopping everything. MedlinePlus says adolescents may play sport if the activity does not cause too much pain, but symptoms improve faster if activity is limited, and some children need a break from most or all sport for 2 months or more. Gloucestershire Hospitals advises reducing aggravating activities to a level the young person can tolerate, and says a balance of rest and exercise is important.
Gloucestershire Hospitals recommends informing the school and asking it to make allowances. It helps for the young person, family and school to agree which activities are reduced for now, how pain will be monitored and when the plan will be reviewed, following the clinician’s advice.
Stretching and strengthening
Gloucestershire Hospitals recommends stretches of the front of the thigh (quadriceps) and back of the thigh (hamstrings), each held for 30 seconds, three times a day, as shown in its leaflet. MedlinePlus notes that regular stretching before and after exercise can help prevent injury.
The right exercises, and how much, depend on the child; a physiotherapist or doctor can tailor them. In severe cases, Gloucestershire Hospitals says specialist insoles from a podiatrist can also help.
Symptom relief and medicine safety
MedlinePlus suggests resting the knee and decreasing activity when symptoms develop, and ice over the painful area 2 to 4 times a day and after activity. Gloucestershire Hospitals suggests a heat pack for 15 minutes before exercise or an ice pack for 20 minutes after exercise to reduce swelling.
Both mention pain-relieving medicines. Gloucestershire Hospitals advises discussing the options with a pharmacist or GP, which is especially important for children, to choose a suitable medicine and dose. MedlinePlus says that rarely a cast or brace, with crutches, is used if symptoms do not go away, and that surgery may be needed in rare cases.
Where the sources differ
Duration. MedlinePlus says most cases improve after a few weeks or months and go away once growth ends. Gloucestershire Hospitals says symptoms generally take 1 to 2 years to go away and may continue until growth is complete.
Playing through pain. Gloucestershire Hospitals says exercise may aggravate the pain but will not cause damage to the knee, in a diagnosed case. MedlinePlus says symptoms improve faster with limited activity and some children need a break from sport.
Surgery. Gloucestershire Hospitals says an operation is not necessary; MedlinePlus says surgery may be needed in rare cases.
In summary
Osgood-Schlatter disease causes pain and swelling over the bump below the knee in growing children and teenagers, usually linked to running and jumping sports during a growth spurt. It is diagnosed by examination, with x-rays only when needed to rule out other causes.
Management combines adjusting activity to a tolerable level, ice or heat, appropriate pain relief and stretches, with the school informed. It almost always settles once growth ends, although the bump may stay larger. Other or unusual knee symptoms need medical review.
Frequently asked questions about Osgood-Schlatter disease
These answers are general information and do not replace an examination or individual medical advice.
What causes Osgood-Schlatter disease?
Repeated strain from the thigh muscle’s tendon pulling on the growing bump below the knee, especially during growth spurts in young people who run, jump or change direction in sport.
Can a child keep playing sport?
Often yes, if the activity does not cause too much pain. Symptoms improve faster when activity is limited, and some children need a break of 2 months or more. Agree the level with a clinician.
How long can symptoms last?
MedlinePlus says most cases improve within weeks or months; Gloucestershire Hospitals says symptoms generally take 1 to 2 years and may continue until growth is complete.
Does the bump always disappear?
No. Gloucestershire Hospitals says the bony bump below the knee may remain enlarged after the symptoms have gone, without long-term complications.
When are X-rays needed?
Not routinely. MedlinePlus says x-rays are rarely needed unless the provider wants to check for other causes of the pain; sometimes one is taken to confirm the diagnosis.
What should family and school agree about activity?
Which activities are reduced for now, how pain will be monitored, what allowances the school will make and when the plan will be reviewed, following the clinician’s advice.
Sources
- MedlinePlus Medical Encyclopedia · Osgood-Schlatter disease (review date 10/20/2024)
- Gloucestershire Hospitals NHS Foundation Trust · Osgood Schlatters Syndrome (OSS), patient information (July 2024)
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.