An osteochondral lesion (OCL) is an area of damage involving the smooth articular cartilage covering the end of a bone and the underlying subchondral bone. In the ankle, these injuries most commonly affect the talus and are often called an osteochondral lesion of the talus (OLT).
Osteochondral lesions frequently develop following an ankle injury such as a significant ligament sprain or fracture, although repetitive loading and other factors may also contribute. The severity can vary considerably – from a small area of cartilage and bone irritation to a larger lesion containing cystic changes or an unstable fragment.
Some lesions cause no symptoms and are discovered incidentally on imaging, while others can cause persistent ankle pain, swelling, stiffness or difficulty returning to sport. Treatment depends on factors including symptoms, lesion size and stability, activity demands and response to conservative management.
Key Facts
- Trauma is involved in most cases. Around 75% of osteochondral lesions of the talus have a history of ankle trauma, such as a sprain or fracture. 🔗
- Not every lesion causes symptoms. Some osteochondral lesions are discovered incidentally on MRI or other imaging and may not require treatment if they are not causing problems. 🔗
- MRI is particularly useful for identifying and characterising osteochondral lesions. 🔗
- An osteochondral lesion can be a “hidden” injury after an ankle sprain. Persistent deep ankle pain after the initial sprain has settled can sometimes be due to an underlying talar osteochondral lesion. 🔗
Risk Factors
- Previous ankle sprain
- Previous ankle fracture
- Recurrent ankle instability
- Repetitive high-impact loading
- Participation in running, jumping or change of direction sports
Symptoms
- Deep ankle pain, particularly during or after weight-bearing activity
- Ankle swelling
- Pain during running, jumping or sport
- Ankle stiffness or reduced range of movement
- Difficulty returning to previous sporting or exercise levels
- Catching, clicking or locking in some cases
- A feeling of instability or giving way, particularly when associated with previous ankle sprains
Aggravating Factors
- Running, jumping and landing
- Change-of-direction activities
- Prolonged walking or standing
- High impact activities or sports
- Uneven surfaces, particularly when ankle instability is also present
Causes
Osteochondral lesions of the talus are most commonly associated with trauma to the ankle. An ankle sprain, fracture or other traumatic injury can compress or shear the cartilage and underlying bone of the talus.
In some people there may not be one obvious injury. Repetitive microtrauma and repeated loading of the ankle may contribute to the development or progression of a lesion. Osteochondritis dissecans represents a related osteochondral condition in which the underlying cause may be more complex and can include repetitive microtrauma and disturbance of the subchondral bone.
How Is It Diagnosed?
Diagnosis usually combines the patient’s history, a physical examination and appropriate imaging.
A physiotherapist or doctor will ask about previous ankle injuries, the location and behaviour of symptoms, swelling, mechanical symptoms and activities that aggravate the ankle. Examination may assess ankle range of motion, joint tenderness, swelling, strength, balance, walking and running mechanics and ankle stability.
Because symptoms can overlap with ankle sprains, tendon injuries, impingement and other ankle conditions, imaging is often required to confirm and characterise an osteochondral lesion.
Investigations & Imaging
- X-ray
- Often an initial investigation. It can identify some bony abnormalities and more established lesions, although smaller osteochondral lesions may not be clearly visible.
- MRI
- Commonly used to assess the cartilage, subchondral bone, bone marrow changes and associated soft-tissue injuries. MRI is particularly useful when an OLT is suspected.
- CT
- Provides detailed assessment of the underlying bone and can be particularly useful for assessing lesion dimensions, cysts and bony architecture.
- Weight-bearing imaging
- May be used when the clinician also needs to assess ankle alignment or other structural factors.
Grading / Classification
- Stable lesion
- Cartilage and osteochondral tissue remain relatively stable without a displaced fragment.
- Partially detached lesion
- The osteochondral fragment may be incompletely separated from the surrounding tissue.
- Displaced lesion
- An osteochondral fragment has separated or displaced and may require surgical assessment.
- Cystic lesion
- Changes or cyst formation have developed within the underlying subchondral bone.
Physiotherapy Management
Management is individualised according to the lesion, symptoms, previous ankle injuries and the patient’s activity or sporting goals. Treatment generally aims to settle symptoms, appropriately manage joint loading, restore ankle movement and strength, improve balance and gradually rebuild tolerance to impact and sport.
Exercise
Exercise rehabilitation may include:
- Ankle mobility exercises
- Calf strengthening
- Tibialis posterior and peroneal strengthening
- Foot and intrinsic muscle strengthening
- Single-leg balance and proprioception
- Hip and lower-limb strengthening
- Running and landing preparation
- Plyometric and change-of-direction exercises
- Sport-specific rehabilitation
Exercise selection and progression should be based on symptoms and the individual’s stage of rehabilitation.
Activity Modification
Temporarily reducing activities that repeatedly aggravate the ankle can allow symptoms to settle while maintaining as much appropriate activity as possible.
Running, jumping and high-impact sport may initially need to be reduced or modified. Lower-impact exercise such as cycling, swimming or appropriately selected strength training may be used to maintain fitness while ankle capacity is rebuilt.
The aim is generally load modification rather than unnecessary complete rest, unless specific restrictions have been provided by an orthopaedic specialist.
Manual Therapy
Manual therapy may be used as an adjunct where ankle stiffness or restricted joint movement is present. Treatment may include ankle joint mobilisation and soft-tissue techniques.
Manual therapy does not repair the osteochondral lesion itself and should usually form part of a broader rehabilitation program.
Heat & Ice
Ice may provide short-term relief when the ankle is painful or swollen following activity.
Heat may be useful for surrounding muscular stiffness in some people but does not directly treat the osteochondral lesion.
Education
Education is an important component of management and may include:
- Understanding the nature and location of the lesion
- Identifying activities that aggravate symptoms
- Appropriate modification of training loads
- Understanding acceptable versus excessive responses to exercise
- Gradually rebuilding ankle capacity
- Managing recurrent ankle instability
- Establishing realistic return-to-running and return-to-sport goals
Other Treatments
Other treatments may occasionally be considered alongside rehabilitation or surgery. These can include injectable or biological therapies, although evidence varies considerably between techniques.
There is currently no single treatment that is clearly superior for every osteochondral lesion. Management should therefore be individualised according to the lesion and the patient’s symptoms and goals.
Surgery
Surgery is not required for every osteochondral lesion. It may be considered when there is an unstable or displaced osteochondral fragment, a lesion with characteristics unlikely to respond adequately to conservative treatment, or persistent symptoms despite an appropriate period of non-operative management.
A review of current treatment concepts notes that operative treatment is generally considered for displaced lesions or symptoms that have failed approximately 3–6 months of non-operative treatment, although decisions are individualised.
Depending on the lesion, surgical options can include arthroscopic debridement, bone marrow stimulation/microfracture, osteochondral grafting or cartilage restoration/regenerative procedures. Lesion size, depth, cyst formation and previous treatment influence the procedure selected.
Prognosis & Return to Activity
The prognosis for an osteochondral lesion varies considerably. Some smaller or stable lesions can be managed successfully without surgery, while larger, unstable, cystic or persistently symptomatic lesions may require orthopaedic management.
Following surgery, many people can return to sport, although recovery time varies according to the procedure. Published rehabilitation protocols show substantial variation, so return to running and sport should be guided by the surgeon’s restrictions and the patient’s clinical progress rather than a universal timeframe
Complications
- Persistent ankle pain
- Recurrent swelling
- Reduced range of motion
- Difficulty tolerating high-impact activity
- Reduced ability to return to previous sporting level
- Enlargement or deterioration of the osteochondral lesion or subchondral cyst formation in some cases
- Development or progression of degenerative joint changes in some patients
Preventing Recurrence
- Appropriate rehabilitation following ankle sprains
- Restore ankle strength before returning to sport
- Balance and proprioceptive training
- Gradually progress running and jumping loads
- Avoid sudden, excessive increases in training volume
- Use appropriate footwear for sport and activity
When to See a Physio
- Ankle pain persists after an ankle sprain or fracture
- Your ankle repeatedly swells after exercise
- Running, jumping or sport continues to cause deep ankle pain
- You have difficulty returning to sport following an ankle injury
- Your ankle repeatedly gives way or feels unstable
- You have persistent restriction in ankle movement
- You have been diagnosed with an osteochondral lesion and require a rehabilitation program
- You require rehabilitation following osteochondral surgery