Osteochondral lesions of the talus (OLTs), otherwise known as osteochondritis dissecans or flake fractures of the talar dome, include a variety abnormalities of the articular cartilage and underlying subchondral bone (1). This may involve separation of a fragment of the articular surface with subsequent loose body formation. The talus is the third most common location for osteochondral lesions following the knee and the elbow (2). The OLTs may occur in up to 6% of all ankle sprains (3, 4, 5). Most patients with symptomatic OLTs are in their 20s or 30s and are active in sports.

It was previously believed that most lesions were either anterolateral with a high association with trauma or posteromedial with a less consistent history of trauma (2,6,7). In contrast to this thinking, a study in 2007 reviewed MRIs from 424 patients with OLTs and found that most lesions were found at the midtalar dome medially or laterally (8). The most commonly affected site was the medial equator at 53% of cases with 26% of cases involving the lateral equator. Also, medial lesions tended to be deeper and involve more surface area.

Pettine and Morrey (9) suggested that the surgeon should initially attempt to treat nondisplaced OLTs with a period of immobilization as these have a chance of healing. Elias et al. (10) reviewed MRIs of non-surgically treated OLTs and found that 45% showed MRI progression with an average follow-up of 13.7 months, 24% improved, and 31% remained unchanged. Bone marrow edema and subchondral cysts noted on the initial MRI were not reliable indicators of lesion progression.

The indication for surgical treatment of OLTs includes failure of conservative management of any stage of lesion. Regardless of the radiographic appearance of a lesion, if the patient is asymptomatic after conservative management they do not necessarily require surgical intervention, even if radiographs fail to show complete
healing. However, patients with loose fragments on plain films, MRI, or CT are candidates for surgery. Acute dome fractures with displacement may be fixed acutely by open reduction and internal fixation with bioabsorbable screws.

The use of osteochondral autograft transplantation (OAT) is indicated in large or cystic lesions and those who have failed previous débridement or marrow stimulating techniques (11). Caution should be exercised in patients with an age >45 (12) because of poor surrounding recipient cartilage and greater donor site morbidity documented with advancing age (11). Also, caution should be taken with lesions >1.5 cm² or cases with avascular necrosis of the talus (11). Defects related to septic arthritis and malignancies are also contraindications. Relative contraindications for using the knee as a donor site include existing arthritic changes, patellofemoral symptoms, and limited range of motion (13).

Patients with OLTs may present after an acute injury, such as an inversion plantarflexion sprain, but more commonly present with a gradual onset of symptoms. These symptoms may include pain, clicking, catching, locking, or giving way. Patients may or may not have signs of ligamentous laxity. The joint line may be tender in the region of the OLT; however, medial lesions are less likely to be directly tender because of their protection by the medial malleolus.

Plain radiographs should be obtained first. Standing anteroposterior, lateral, and mortise radiographs should be obtained. More posterior lesions may be better visualized with plantarflexion of the ankle. Conversely, anterior lesions may be better visualized with dorsiflexion of the ankle.

Berndt and Harty’s radiographic classification of OLTs is commonly used for classification of these lesions; however, correlations with arthroscopic findings are poor (14). Thus, Ferkel and Sgaglione proposed a four-stage classification of these lesions based on CT scan findings (15) (Fig. 54.1

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