Complete Ankle Joint that is Tibiotalar and Distal Tibiofibular Coalition Presenting with Foot and Ankle Pain - A Case Report

Introduction: Coalition is an abnormal, usually congenital, or developmental connection in between or the complete fusion of two bones that are otherwise separate. It is of three types, i.e., synostosis (bony connection), synchondrosis (cartilaginous connection), or syndesmosis (fibrous tissue). Its typical cause is the failure of mesenchymal segmentation and differentiation. Usually, it is seen in tarsal or carpal bones and very rarely in between other bones. Only a single case of a tibiotalar coalition has been reported previously in literature. Herein, we are reporting a case of the talocrural coalition, which is the first one from the Indian sub-continent.

Case report: A 16-year-old moderately built female patient of Indian origin presented with chronic pain of 1-year duration in the right foot and ankle region on weight bearing. The pain was dull aching type, mild-to-moderate in severity and worsened with activity or prolonged walking, and relieved on taking non-steroidal anti-inflammatory drugs. No relevant history was present. On local examination, diffuse tenderness was present in the ankle and the tarsal bones. Almost negligible dorsiflexion and about 15° plantar flexion of the foot were possible. An initial radiograph of the right ankle revealed osseous fusion between the distal tibia and fibula, as well as between the tibia, fibula, and the dome of the talus. Magnetic resonance imaging (MRI) revealed osseous fusion involving the distal tibia, fibula, and the dome of the talus (both medially and laterally), indicative of talocrural fusion. No edema or inflammation was appreciable in the adjacent tendons or synovium. The patient was explained regarding the pathology and the prognosis. She was managed conservatively and was satisfied.

Conclusion: Radiographs play a crucial role in evaluating patients suspected of having a coalition or ankylosis. Complementary tools such as computed tomography and MRI are valuable for a more in-depth assessment of the fusion and aid in surgical planning.