SUMMARY
Osteochondral lesions of the talus are focal injuries of the talar dome involving articular cartilage with variable subchondral bone involvement. Lesions may arise after a single traumatic event or repetitive microtrauma and can progress to chronic pain, mechanical symptoms, and ankle arthritis if untreated. Diagnosis relies on imaging, often MRI for lesion characterization and treatment ranges from nonoperative management to advanced cartilage restoration techniques depending on lesion size, stability, chronicity, and patient factors.
EPIDEMIOLOGY
Frequently associated with ankle trauma
~70% of ankle sprains
~75% of ankle fractures
Bilateral lesions in ~10%
Medial talar dome lesions are more common than lateral lesions
Incidence higher in males
ETIOLOGY & PATHOPHYSIOLOGY
Mechanism of Injury
Lateral talar dome lesions
Ankle inversion + dorsiflexion under axial load
Typically traumatic
Medial talar dome lesions
Ankle inversion + external rotation + plantarflexion under axial load
Often no clear trauma history
Pathophysiology
Acute shearing injury or repetitive microtrauma
Possible ischemic environment in subchondral bone
Progressive loss of subchondral support → cartilage softening, fragmentation, or cyst formation
Associated Conditions
Chronic lateral ankle instability
Cavovarus hindfoot alignment
Untreated ligament insufficiency (increases failure rates after OLT surgery)
ANATOMY
Talus
Geometrically complex, frustum-shaped
Anterior portion wider than posterior
No muscular attachments → vulnerable to injury
~70% covered by cartilage (thick, durable cartilage)
Blood Supply
Predominantly extraosseous
Deltoid artery supplies most of the talar body and dome
Limited vascularity contributes to poor healing potential
LESION LOCATION CHARACTERISTICS
Medial Talar Dome
Most common
Posterior location
Larger, deeper, cup-shaped
Often nondisplaced
Less reliable trauma history
Higher incidence of subchondral cysts
Lateral Talar Dome
Less common
More anterior or central
Smaller, more superficial
Usually displaced
Strong traumatic association
Lower spontaneous healing potential
More often symptomatic
CLASSIFICATION SYSTEMS
Berndt & Harty (Radiographic)
Stage I: Subchondral compression
Stage II: Partial fragment detachment
Stage III: Complete but nondisplaced fragment
Stage IV: Displaced fragment
Ferkel & Sgaglione (CT-based)
Emphasizes cyst formation, fragment stability, and articular communication
Hepple (MRI-based)
Includes cartilage integrity, bone edema, displacement, and cyst formation (Stages I–V)
PRESENTATION
History
Prior ankle sprain (often inversion injury)
Chronic ankle pain after “minor” injury
Persistent symptoms despite conservative care
Symptoms
Deep ankle joint pain
Recurrent swelling
Mechanical symptoms (locking, catching, giving way)
Physical Examination
Joint effusion common
Palpation often non-localizing
Limited ROM due to pain or effusion
Assess:
Hindfoot alignment (cavovarus)
Ligamentous stability (critical for surgical success)
IMAGING
Plain Radiographs
Weight-bearing AP, mortise, lateral
Often normal
May show subtle lucency or fragment
CT
Best for:
Subchondral bone evaluation
Cyst size and depth
Surgical planning
Limited for pure cartilage lesions
MRI
Imaging modality of choice
Defines:
Lesion size and stability
Bone marrow edema
Cartilage integrity
Fluid signal beneath subchondral bone → unstable lesion
Highly sensitive for predicting lesion stability
TREATMENT
NONOPERATIVE MANAGEMENT
Indications
Acute, stable, nondisplaced lesions
Incomplete fractures
Method
Immobilization and non–weight bearing (≈6 weeks)
Gradual return to activity with physical therapy
Outcomes
~45% good–excellent results
Best in acute, small, stable lesions
OPERATIVE MANAGEMENT
1. Arthroscopic Debridement & Marrow Stimulation (Microfracture / Drilling)
Indications
Chronic lesions
Size <1 cm²
Unstable cartilage or poor healing potential fragment
Outcomes
80–85% pain improvement
Fibrocartilage formation common
2. Retrograde Drilling ± Bone Grafting
Indications
Lesions >1 cm²
Intact cartilage cap
Subchondral cysts
Key Point
Preserves cartilage surface
Fluoroscopy-guided
3. Osteochondral Grafting (OAT, Allograft, ACI, MACI)
Indications
Large (>1–1.5 cm²)
Cystic lesions
Shoulder lesions
Failed prior surgery
Techniques
Osteochondral autograft transplantation (OATS)
Fresh osteochondral allograft
Autologous chondrocyte implantation (ACI / MACI)
Contraindications
Diffuse ankle arthritis
Bipolar (“kissing”) lesions
Advanced talar osteonecrosis
SURGICAL APPROACH CONSIDERATIONS
Arthroscopy preferred whenever possible
Medial malleolar osteotomy for posterior medial lesions
Lateral lesions may require ATFL/CFL release
Address ankle instability and malalignment concurrently
COMPLICATIONS
Graft failure
Persistent pain
Osteotomy nonunion
Donor site morbidity
Progression to ankle arthritis
PROGNOSIS
Lesions may progress to involve entire ankle joint
Outcomes depend on:
Lesion size and stability
Quality of reduction/restoration
Correction of instability or malalignment
Early diagnosis improves long-term joint preservation