Ultrasound of talocalcaneal coalition: retrospective study of 11 patients.

OBJECTIVE

To present the ultrasound appearance of talocalcaneal coalitions (TCC).

MATERIALS AND METHODS

We present a retrospective review of 11 patients (8 women and 3 men, age range 17-58 years, mean age 35.3 years) in which ultrasound, the first imaging study carried out, detected a TCC that was not known or suspected clinically. Patients were subsequently examined by standard radiographs, computed tomography (CT) or magnetic resonance imaging (MRI).

RESULTS

In 9 patients with fibrous coalition ultrasound showed a reduced joint space of the medial aspect of the anterior talocalcaneal joint associated with an irregular, pointed appearance of its outline. In 2 patients with osseous coalitions ultrasound revealed a smooth continuity of the hyperechoic bone surface between the medial talus and the substentaculum tali. The diagnosis was confirmed in 4 patients with CT and in 3 with MRI. In the remaining 4 patients standard radiographs were consistent with TCC.

CONCLUSION

Owing to its tomographic capabilities ultrasound can detect TCC. We suggest that study of the anterior subtalar joint should be a part of every ankle ultrasound examination as it can show a clinically unsuspected TCC. Confirmation of the coalition by CT or MRI is required in the preoperative assessment to better assess the type and extent of the congenital anomaly as well as the adjacent joints.