Osteochondritis Dissecans of the Knee in Children: Symptoms and Treatment

Osteochondritis dissecans (OCD) of the knee in children is a condition that affects the bone and cartilage inside a joint.

It commonly develops in children and adolescents whose bones are still growing.

The condition occurs when a small area of bone beneath the joint cartilage becomes damaged, potentially affecting the cartilage covering it.

Children may initially experience knee pain during running, jumping or playing sports.

As the condition progresses, symptoms can include swelling, stiffness, reduced movement and, in more advanced cases, locking of the knee.

Early diagnosis is important because some lesions heal with activity modification and appropriate treatment, while others may require surgery.

The outcome depends on the child’s age, growth plate status, lesion size, location and stability.

Physiotherapy also has an important role in recovery.

A carefully planned rehabilitation program helps restore knee movement, muscle strength, balance and functional control before the child gradually returns to sports.

What Is Osteochondritis Dissecans of the Knee?

Osteochondritis dissecans is a joint condition involving the subchondral bone, which is the layer of bone located directly beneath the smooth cartilage covering the ends of bones.

In the knee, OCD most commonly affects the rounded ends of the thigh bone, called the femoral condyles.

The area on the inner side of the knee, known as the medial femoral condyle, is most frequently involved.

As the affected bone becomes damaged, the overlying cartilage may lose its support. In some children, the affected area remains attached to the surrounding bone.

In others, it may become unstable or separate completely.

If a fragment becomes loose inside the joint, it can interfere with normal knee movement and cause catching or locking.

OCD in children is commonly called juvenile osteochondritis dissecans (JOCD).

It refers to the condition in children and adolescents who still have open growth plates. (Akkawi et al., 2024)

Why Is Juvenile Osteochondritis Dissecans Different From Adult OCD?

The main difference is whether the child’s bones are still growing.

Juvenile OCD	Adult OCD
Occurs in children with open growth plates	Occurs after skeletal maturity
Stable lesions have a better chance of healing without surgery	Healing with non-surgical treatment is generally less predictable
Bone is still developing	Bone growth has largely finished
Treatment often begins with activity modification for suitable stable lesions	Surgery may be considered more readily, depending on the lesion

Children with open growth plates generally have better healing potential, particularly when the lesion is stable and identified early.

However, age alone does not determine the outcome. A large or unstable lesion in a young child may still require surgery.

What Causes Osteochondritis Dissecans in Children?

The exact cause of OCD is not fully understood. Researchers believe that several factors may contribute to its development.

Possible contributing factors include:

Repetitive Stress on the Knee

Repeated running, jumping, landing and twisting can place stress on the knee joint. Over time, repetitive loading may contribute to damage in the bone beneath the cartilage.

Repeated Minor Injuries

Small injuries that occur during sports or physical activity may contribute to the development of a lesion in susceptible children.

Changes in Blood Supply

Reduced blood supply to a small area of bone has been proposed as one possible explanation for OCD. However, this mechanism has not been established in every case.

Genetic and Developmental Factors

Family history, inherited susceptibility and differences in bone development may also contribute.

Sports participation does not automatically cause OCD. Many active children never develop the condition, and some children diagnosed with it have no clear history of repetitive injury.

Which Children Are More Likely to Develop OCD?

OCD is most commonly identified in school-aged children and adolescents, particularly those involved in regular physical activity.

It is frequently diagnosed in children participating in sports involving repeated impact or changes in direction, such as:

• Football
• Basketball
• Gymnastics
• Athletics
• Tennis
• Volleyball

However, the condition is not limited to young athletes. Children who do not participate in organised sports can also develop OCD.

What Are the Symptoms of Osteochondritis Dissecans in Children?

Symptoms often develop gradually. Early symptoms may be mild and noticeable only during or after physical activity.

1. Knee Pain During Activity

Pain is one of the most common symptoms. Children may experience discomfort while running, jumping, climbing stairs or playing sports.

Initially, the pain may improve with rest. As the condition progresses, discomfort may occur during ordinary activities.

2. Swelling Around the Knee

Some children develop swelling around the knee, particularly after physical activity.

Repeated swelling should not be ignored because it may indicate irritation inside the joint.

3. Knee Stiffness

The knee may feel stiff after sitting for a long time or following exercise.

Some children may find it difficult to bend or fully straighten the affected leg.

4. Reduced Physical Performance

A child may begin avoiding sports, running or jumping because of discomfort.

Parents may notice that the child is slower than usual, struggles to participate in physical education or frequently complains of knee pain after activity.

5. Catching or Locking of the Knee

An unstable or detached fragment may interfere with normal joint movement.

Children may describe a catching sensation, clicking or difficulty moving the knee through its full range.

A knee that becomes genuinely locked and cannot straighten normally needs prompt medical assessment.

Which Part of the Knee Is Usually Affected?

The most common location is the lateral aspect of the medial femoral condyle, which is part of the thigh bone forming the inner side of the knee joint.

Less commonly, OCD can affect the lateral femoral condyle, kneecap or other areas of the knee.

The location matters because it can influence the lesion’s response to treatment and its likelihood of healing.

How Is Osteochondritis Dissecans Diagnosed?

Diagnosis involves reviewing the child’s symptoms, performing a physical examination and using imaging investigations.

Physical Examination

The clinician may assess:

• Location and severity of knee pain
• Swelling and tenderness
• Knee bending and straightening
• Walking pattern
• Quadriceps strength
• Knee alignment and stability

The examination also helps identify other conditions that may cause similar symptoms.

X-rays

X-rays are commonly the first imaging investigation.

They help identify the location and size of the lesion, assess the growth plates and look for changes in the underlying bone.

Special views may be required to examine areas that are difficult to see on standard X-rays.

MRI Scan

MRI provides detailed information about the bone, cartilage and surrounding tissues.

It helps assess the extent of the lesion and look for signs that the affected fragment may be unstable.

However, MRI findings do not always establish stability with complete certainty in children.

The results must be interpreted alongside the child’s symptoms, physical examination and X-ray findings. (Akkawi et al., 2024)

Can Osteochondritis Dissecans Affect Both Knees?

Yes. Although OCD commonly affects one knee, lesions can sometimes be present in both knees.

A child diagnosed with OCD in one knee may therefore need assessment of the opposite knee, particularly if there are symptoms or clinical reasons to suspect involvement.

Bilateral assessment is useful because some lesions may not cause noticeable symptoms during the early stages.

What Are the Stages of Osteochondritis Dissecans?

OCD lesions are commonly described according to whether the affected area remains attached to the underlying bone.

Stable Lesion

The affected bone and overlying cartilage remain attached.

These lesions are more likely to respond to non-surgical treatment, particularly in younger children with open growth plates.

Unstable Lesion

The affected fragment shows signs of separation from the surrounding bone.

These lesions have a lower likelihood of healing with activity modification alone.

Displaced Fragment

The affected fragment has separated and may move within the knee joint.

This can cause locking, catching and restricted movement. Surgical assessment is generally required.

Understanding lesion stability is essential because it helps the orthopedic specialist decide whether conservative treatment or surgery is more appropriate.

How Is Osteochondritis Dissecans Treated in Children?

Treatment depends on the child’s skeletal maturity, lesion size, location, stability and symptoms.

The main goals are to protect the affected area, support bone healing and preserve the joint surface.

1. Activity Modification

Children with stable lesions are usually advised to stop high-impact activities temporarily.

This may include avoiding:

• Running and sprinting
• Jumping and landing
• Competitive sports
• Repeated twisting and pivoting
• Activities that increase knee pain

The child may be allowed to continue selected low-impact activities, depending on medical advice.

2. Weight-Bearing Restrictions

Some children may need temporary restrictions on how much weight they place through the affected leg.

Crutches, braces or other forms of support may be recommended depending on the lesion and symptoms.

These measures are not necessary for every child.

3. Monitoring and Follow-up

Stable lesions are often managed initially without surgery.

Regular medical reviews and follow-up imaging help assess whether the affected bone is healing.

Activity restrictions may be adjusted according to the child’s progress.

4. Surgical Treatment

Surgery may be considered when:

• The lesion is unstable or displaced.
• A loose fragment causes locking or other mechanical symptoms.
• A stable lesion does not heal after an appropriate period of non-surgical treatment.
• The joint surface needs to be repaired or restored.

Depending on the condition of the fragment, surgical procedures may include drilling to stimulate healing, fixation of a fragment that can be preserved, or cartilage and bone restoration procedures when necessary.

The orthopedic surgeon selects the procedure according to the lesion’s characteristics.

The American Academy of Orthopedic Surgeons (AAOS) clinical practice guideline discusses diagnosis and treatment considerations for both skeletally immature and mature patients with knee OCD. (AAOS, 2023)

How Does Physiotherapy Help Children With Osteochondritis Dissecans?

Physiotherapy supports recovery by addressing stiffness, muscle weakness, reduced movement control and loss of physical fitness.

However, rehabilitation must be planned according to the lesion’s stability and the orthopedic treatment plan.

Starting strengthening or weight-bearing exercises too early may place unnecessary stress on the affected area.

1. Restoring Knee Movement

Periods of reduced activity, bracing or immobilization can lead to knee stiffness.

Once movement is permitted, the physiotherapist may introduce gentle range-of-motion exercises to improve knee bending and straightening.

The progression should follow the treating specialist’s instructions.

2. Improving Quadriceps Strength

The quadriceps muscles help control knee movement and support activities such as walking, climbing stairs and standing up.

Reduced activity can lead to quadriceps weakness.

Depending on the stage of healing, rehabilitation may include:

• Quadriceps activation exercises
• Straight-leg raises
• Controlled knee movement exercises
• Progressive strengthening

These exercises should be introduced only when permitted and adjusted to avoid excessive loading.

3. Strengthening the Hip and Lower-Limb Muscles

The hip muscles, hamstrings and calf muscles contribute to lower-limb control during movement.

A physiotherapist may gradually introduce strengthening exercises to improve overall leg function and movement coordination.

4. Improving Balance and Coordination

Knee pain and reduced activity can affect balance and confidence when standing or walking.

Balance exercises may progress from supported standing activities to more challenging single-leg exercises as recovery allows.

5. Correcting Walking and Movement Patterns

Some children develop compensatory movement patterns because of pain or weakness.

Physiotherapy may include gait retraining and functional movement exercises to improve walking mechanics and lower-limb control.

6. Gradual Return to Running and Sports

Returning to sports requires more than simply becoming pain-free.

Once the treating specialist confirms sufficient healing, rehabilitation may gradually progress to:

• Walking and controlled jogging
• Progressive strengthening
• Squatting and step exercises
• Single-leg balance and control
• Running and direction-change drills
• Sport-specific movements

The child should not return to competitive sports until the medical team is satisfied with healing and functional recovery.

Physical therapy after appropriate medical treatment aims to restore movement and strength while supporting a controlled return to activity. (Mohr et al., 2024)

How Long Does Osteochondritis Dissecans Take to Heal?

Recovery varies from child to child.

Younger children with stable lesions and open growth plates may respond well to non-surgical treatment.

However, healing can take several months and sometimes longer.

Many stable lesions are initially managed with a period of activity restriction and monitoring, often lasting around three to six months before the treatment response is reassessed.

Children who require surgery may need additional time for bone healing and rehabilitation.

Pain relief alone does not confirm that the lesion has healed.

Clinical assessment and follow-up imaging help guide decisions about increasing activity and returning to sports.

Can Osteochondritis Dissecans Be Prevented?

There is no guaranteed way to prevent OCD because its exact cause is not fully understood.

However, healthy training habits may help reduce excessive repetitive stress on growing joints.

Parents and coaches can encourage children to:

• Increase training intensity gradually.
• Avoid sudden increases in sports participation.
• Include adequate recovery between demanding sessions.
• Maintain strength and movement control.
• Report persistent knee pain rather than playing through it.
• Follow medical advice when recovering from an injury.

These measures support healthy physical activity but cannot guarantee that OCD will not develop.

What Happens If Osteochondritis Dissecans Is Left Untreated?

Some stable lesions may heal with appropriate treatment and monitoring. However, an unstable lesion that does not heal can progress to fragment separation.

Potential complications include:

• Persistent knee pain
• Recurrent swelling
• Reduced knee movement
• Loose fragments inside the joint
• Damage to the joint cartilage
• Increased risk of early degenerative joint changes

Early assessment helps identify children who may need closer monitoring or surgical treatment.

When Should Parents Seek Medical Advice?

Parents should arrange a medical assessment if a child experiences persistent knee pain during or after physical activity.

Medical attention is particularly important when symptoms include:

• Recurrent knee swelling
• Pain that does not improve with rest
• Difficulty walking or bearing weight
• Reduced ability to bend or straighten the knee
• Repeated catching or locking sensations

Seek prompt medical attention if the knee becomes locked, the child cannot bear weight, or there is significant swelling and severe pain.

Children should not be encouraged to continue sports through persistent knee pain.

Conclusion

Osteochondritis dissecans of the knee is an important condition to recognize in growing children and young athletes.

It affects the bone beneath the joint cartilage and can range from a stable lesion that responds to non-surgical treatment to an unstable fragment that requires surgery.

Early diagnosis, appropriate activity modification and regular orthopaedic follow-up are essential for protecting the developing knee joint.

Physiotherapy supports recovery by restoring safe movement, rebuilding muscle strength, improving balance and preparing children for a gradual return to sports.

Rehabilitation should always match the stage of healing and the treating specialist’s recommendations.

With timely assessment and appropriate care, many children with stable OCD lesions can recover and return to their usual activities.

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