Osteochondritis Dissecans of the Tarsal Navicular Bone: Imaging Findings in Four Patients

Abstract

We report the imaging characteristics of osteochondritis dissecans of the tarsal navicular bone in four cases and review the current literature. Its radiological findings are similar to osteochondritis dissecans found in other sites: focal lucency that disrupts the sharp cortical line, the presence of sclerosis, and cortical depression.

Osteochondritis Dissecans of the Tarsal Navicular

“…To our knowledge, MRI appearance of tarsal navicular OCD has been described in only one article. 1 However the CT appearance of tarsal navicular OCD has not been reported in the literature. The differential diagnosis of tarsal navicular OCD includes osteonecrosis, stress fracture and the Mueller-Weiss syndrome.…”

“…A 27-year-old male athlete presented with chronic right dorsal midfoot pain and limitation in midfoot movements. Laboratory studies including erythrocyte sedimentation rate 1 and complete blood count were within normal limits. A lateral radiograph of the right foot showed subtle cortical depression and sclerosis in the proximal articular surface of the tarsal navicular ( Figure 1).…”

Imaging of Tarsal Navicular Disorders

“…The exact etiology of OCLs is unknown, but ischemia and trauma are believed to play important roles in their development. 66-68 OCLs of the navicular are confined to the central aspect of the proximal articular surface. This location gives credence to both the purported etiological factors.…”

“…Early navicular OCLs are difficult to detect radiographically. X rays are often normal, but they may reveal subtle sclerosis, flattening, or cortical interruption of the navicular’s proximal articular surface 68,70 (Figure 12). MRI best reveals the changes of early lesions by demonstrating increased T2/STIR signal underlying the site of cartilaginous injury.…”

“…68 CT and MRI are more useful for evaluating these OCLs because they can reveal the full extent of a lesion. 68 CT reveals disruption at the central, proximal articular surface of the navicular, which on coronal views appears as a cortical depression with surrounding sclerosis. 68 A focal lucent lesion can also be seen.…”