Beyond Osteochondral and Ligamentous Injuries of the Ankle: A New Focus on Other Overlooked Pathologies on CT Arthrography of the Ankle

CT arthrography is a reasonable imaging tool that has been utilized in the ankle in sustained post-sprained pain and ankle impingement syndromes. The main indications of CT arthrography are to assess the osteochondral and chondral lesions, in both situations; many other non-osseous non-chondral pathologic changes could be adequately observed in the same study. The aim of this study was to demonstrate the ability of CT arthrography of the ankle to detect a not uncommon group of injuries other than the osteochondral, chondral, and ligamentous lesions in internal derangement of the ankle joint. Forty-seven patients diagnosed with osteochondral lesion or suspected to have hyaline chondral defect of the ankle joint underwent CT arthrography of the ankle. The synovial and joint space pathologic features are the most frequent observed findings, and the other interesting findings were the uneven joint space widening and the extra-articular pathologic changes in posterior ankle and hind foot locations. There were significant reasonable positive correlations between high VAS score with the presence of synovial thickening and tarsal sinus abnormalities. Regarding the complications of arthrographic procedure, two minor complications have occurred, the inadvertent extra-articular contrast injection and vasovagal syncope, and no major complication has occurred. CT arthrography of the ankle is a helpful imaging tool that could benefit from the extra-articular flow of contrast beyond the talo-crural joint cavity to reveal many pain-producing pathologic conditions other than the osteochondral, chondral, and ligamentous lesions. It could also benefit from procedural joint distension to support diagnosis of mechanical ankle instability although being a static imaging modality.