Osteochondritis dissecans of the knee may not cause any symptoms, but some people may experience pain and swelling. Engaging in competitive sports may contribute to its development.

Doctors may provide conservative treatment to help the condition heal. However, not seeking treatment may risk complications or the need for surgery.

This article looks at osteochondritis dissecans of the knee and outlines its causes, symptoms, diagnosis, treatment options, and more.

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Pain and swelling are the most common first symptoms of osteochondritis dissecans. It typically occurs due to physical activity or playing sports.

Around 80% of people with osteochondritis dissecans of the knee experience pain when weight bearing.

In juvenile osteochondritis dissecans, the pain is more likely to come and go and typically occurs due to physical activity.

Adults are more likely to experience:

However, knee osteochondritis dissecans may be asymptomatic, meaning a person has no symptoms. Therefore, doctors may discover the condition incidentally.

Osteochondritis dissecans occurs when a lack of blood supply causes a small piece of bone to separate from its surroundings. This causes the piece of bone and its cartilage to loosen and crack.

Experts do not know exactly what causes this to happen. However, it is possibly due to stress to the bone or repetitive trauma.

It may be more likely to occur in adults due to vascular injury in the knee. Juvenile osteochondritis dissecans is the result of repetitive high impact activities.

Risk factors

Age may be a risk factor for osteochondritis dissecans of the knee. It is more common in younger people, with those aged 12–19 years at greater risk than younger children.

In addition, males are more likely to develop the condition than females.

Osteochondritis dissecans in children and young teenagers may resolve without treatment. Children’s symptoms typically improve within 2–4 months if they rest and avoid strenuous physical activity.

Medical professionals may decide on more conservative treatments, such as:

  • using crutches to reduce weight bearing
  • immobilizing the knee with a splint or cast
  • muscle-strengthening exercises
  • physical instrumental therapies, such as extracorporeal shock wave therapy

Doctors may recommend surgery if:

  • conservative treatments do not alleviate symptoms
  • the lesion detaches from the surrounding bone
  • the lesion is greater than 1 centimeter in diameter

There are different types of surgery that a doctor may recommend, including:

  • drilling the lesion to create a new pathway so that blood vessels can reach the affected area
  • using screws and pins to hold the lesion in place
  • inserting a new piece of bone and cartilage to replace the damaged ones

A person’s doctor can offer advice, recommend the best treatment, and answer any questions a person has.

If someone has pain, swelling, or other symptoms in the knee, contact a doctor. The doctor may begin the diagnosis by performing a physical examination, asking questions about symptoms, and taking a full medical history.

They may then order various tests, which can include an X-ray and an MRI. The tests can provide detailed images of the knee so the doctor can identify any loose bone.

Osteochondritis dissecans of the knee happens when a small piece of bone separates from its surroundings. It may cause swelling and pain, particularly when putting weight on the joint. However, some people may not experience any symptoms.

While experts do not fully understand why this condition happens, they think younger people who participate in competitive sports or high impact physical activities are more at risk.

For children, the condition may heal on its own with rest. A doctor may also recommend crutches to reduce the amount of weight on the joint and a splint to immobilize the joint. Sometimes, surgery may also be an option.

Contact a doctor with any concerns about osteochondritis dissecans of the knee. They can make a diagnosis and advise on a suitable treatment plan if required.