Osteochondral lesions of the ankle

In brief

An osteochondral lesion is damage to the joint cartilage and the bone immediately beneath it. In the ankle it mainly affects the talus. It can appear after an injury such as a sprain, or with no clear history, and cause persistent pain, swelling, limitation in sport and, if there is an unstable fragment, joint locking.

Typical age

Older children and adolescents

Also known as

Osteochondritis dissecans of the talus · Osteochondral lesion of the talus

What is it?

The talus is the bone that connects the leg to the foot and forms part of the ankle joint. Its surface is covered with cartilage, a smooth tissue that lets the bones glide over each other with minimal friction. Beneath the cartilage lies the subchondral bone, which supports the joint surface.

An osteochondral lesion occurs when the cartilage, the subchondral bone or both are damaged. In children and adolescents it can be related to an injury, especially a sprain, although sometimes there is no clear triggering event. The lesion can range from a localised change in the bone with apparently intact cartilage to a partly detached or unstable osteochondral fragment.

These lesions most often affect the talus and are usually located on the inner or outer part of its joint surface. How they progress depends on factors such as the size and depth of the lesion, the stability of the cartilage, the presence of bone cysts and the patient’s skeletal maturity.

Not all osteochondral lesions need surgery. Some improve with conservative treatment, while others require surgical techniques aimed at stimulating bone repair, treating the damaged cartilage or stabilising a fragment when it is viable.

Early diagnosis and choosing the right treatment are essential to preserve the joint surface and support functional recovery.

Signs parents may notice

Symptoms may appear immediately after an injury or develop gradually over weeks or months.

• Persistent ankle pain, especially when running, jumping or playing sport.
• Recurrent swelling, which may increase after physical activity.
• Discomfort when putting weight on the foot or bending and straightening the ankle.
• Limitation in sport: the child stops running, jumping or training normally because of pain.
• A feeling of the joint locking or catching, especially if there is an unstable fragment.
• Pain after a sprain that does not improve as expected with the usual treatment.

Ankle pain that persists after a sprain should not always be put down to a ligament injury. In some cases there may be an associated osteochondral lesion.

When to see a specialist

A specialist assessment is advisable when the child or adolescent has:

• Ankle pain that persists after a sprain.
• Repeated swelling or pain related to sport.
• Difficulty returning to their usual activity after an injury.
• A feeling of locking, catching or loss of ankle movement.
• Symptoms that come back every time physical activity increases.

When is it urgent?

If the child cannot put weight on the foot after an injury, or there is deformity, severe pain or sudden marked swelling, an urgent medical assessment is needed. A hot, red ankle with fever also requires urgent attention.

How is it diagnosed?

The diagnosis combines clinical examination with imaging to determine the location, size and stability of the lesion.

Clinical examination

The specialist assesses where the pain is, ankle movement, any joint effusion and ligament stability. Previous injuries and the impact of the symptoms on walking and sport are also explored.

X-rays

These are usually the first imaging test. They can show bone changes, osteochondral fragments and some signs of injury to the talus. However, early lesions or those affecting mainly the cartilage may not be visible.

Magnetic resonance imaging (MRI)

MRI is particularly useful for assessing the cartilage, the subchondral bone, bone oedema, cysts and the stability of the lesion. It can also show associated injuries to the ligaments and other soft tissues.

Computed tomography (CT)

In selected cases, CT gives detailed information about the bone structure, the depth of defects and the presence of fragments or cysts. It can be useful when planning certain surgical procedures.

The choice of tests depends on the clinical suspicion and the initial results. MRI plays a particularly important role when symptoms persist and X-rays do not explain the clinical picture.

Treatment

Treatment is tailored to the patient’s age, skeletal maturity, the size and depth of the lesion, the stability of the fragment and the response to conservative measures.

The aim is to relieve pain, restore ankle function and preserve the joint surface in the long term.

Conservative treatment

For selected stable lesions, especially when there is no displaced fragment, non-surgical treatment may be tried first.

This can include:

• Reducing sport: temporarily avoiding running, jumping and impact activities that cause pain.
• Offloading or limiting weight-bearing: depending on the lesion, crutches may be needed for a period.
• Temporary immobilisation: in some cases a walking boot or cast is used to protect the lesion.
• Pain control: with medication when prescribed by the doctor.
• Progressive rehabilitation: once progress allows, work on mobility, strength, balance and neuromuscular control.

The length of treatment depends on the lesion and its clinical and imaging progress. During follow-up, the specialist checks that the pain is decreasing and that the patient is gradually regaining function.

If symptoms persist, the lesion is not progressing well or there are signs of instability, the treatment strategy should be reconsidered.

Surgical treatment

Surgery may be indicated when pain and functional limitation persist despite appropriate conservative treatment, or when there is an unstable or displaced fragment that needs specific treatment.

The choice of technique depends on the characteristics of the lesion and whether the joint surface can be preserved or restored.

1. Ankle arthroscopy

Arthroscopy gives access to the inside of the joint through small incisions and a high-definition camera. It allows direct visualisation of the lesion and treatment of certain cartilage and subchondral bone problems.

Its advantages include being able to assess the stability of the fragment, treat selected lesions and deal with other problems inside the joint when present.

2. Drilling and stimulation of bone repair

For certain small, contained lesions with no viable fragment that needs fixing, the subchondral bone can be drilled arthroscopically. This technique aims to stimulate a repair response by the body, bringing in cells and factors involved in forming repair tissue.

Whether it is suitable depends on the depth and extent of the defect, the condition of the cartilage and the anatomy of the lesion. The repair tissue that forms is not identical to the original joint cartilage, so careful patient selection is important.

3. Platelet-rich plasma (PRP)

Platelet-rich plasma is obtained from the patient’s own blood and contains a concentration of platelets that release growth factors. It is used in certain settings to support tissue repair.

In osteochondral lesions of the talus, PRP may be considered as an add-on treatment in selected cases. However, the scientific evidence is still mixed and does not allow it to be regarded as a universal solution or a substitute for the surgical techniques indicated by the shape of the lesion.

Whether to use it should be decided case by case, explaining to the family the expected benefits and the limitations of the available evidence.

4. Treatment of unstable fragments and larger lesions

When there is a displaced or potentially viable osteochondral fragment, fixing it may be considered to try to preserve the joint surface. For larger defects, cystic lesions or cases that do not respond to initial procedures, specific reconstructive techniques may be needed.

The choice depends on the quality of the fragment, the condition of the subchondral bone, the extent of the defect and any previous treatments.

A specialised approach to ankle arthroscopy

Dr. Laura Corominas assesses foot and ankle injuries in children and adolescents, with particular attention to osteochondral lesions of the talus and treatment options tailored to each patient.

For cases that require arthroscopic treatment, she works with a specialist experienced in ankle arthroscopy. This joint approach allows coordinated assessment of the lesion and planning of procedures such as subchondral bone drilling and other joint-preserving techniques when indicated.

Treatment decisions are based on the characteristics of the lesion, the patient’s age and their functional needs, always aiming to preserve the joint and enable a safe return to sport.

Outlook and recovery

Recovery depends on the type of lesion and the treatment carried out. There is no single timeline that applies to all patients.

• Conservative treatment: may require several weeks of reduced load or immobilisation, with clinical and, when indicated, imaging check-ups.
• First weeks after surgery: crutches, limited weight-bearing or protection with a boot or cast may be needed, depending on the procedure.
• School: a return is usually possible before a return to sport, as long as the pain is under control and getting around is safe.
• Rehabilitation: introduced gradually to restore mobility, strength, balance and neuromuscular control.
• Return to sport: often takes several months, depending on the lesion and the technique used. It should be allowed when clinical progress and, if appropriate, imaging are satisfactory.

Specialist follow-up is important to detect persistent symptoms, assess how the lesion is healing and adjust the progression of physical activity.

The ultimate goal is a functional, stable ankle with as little pain as possible and the best conditions for staying active in the long term.

Osteochondral lesions of the talus can be a cause of persistent pain in children and adolescents, especially after an ankle sprain. An accurate diagnosis distinguishes them from other causes of pain and allows the most suitable treatment to be chosen according to the size, location and stability of the lesion and the patient’s age.

This page is for general information and does not replace an assessment by a specialist. If you are worried about your child's foot, talk to their paediatrician or book an appointment.