Diagnostic value of high-frequency ultrasonography for painful talocalcaneal coalition and its complications

To investigate the value of high-frequency ultrasonography in the diagnosis of painful talocalcaneal coalition (TCC) and its complications. Seventy-seven patients (84 feet) with abnormal mass and pain in the medial malleolus were suspected of TCC pre-operatively and examined by high-frequency ultrasonography, radiograph, and CT. The sonographic characteristics of the affected feet were analyzed pre-operatively and compared with the surgical findings. During the operation, 49 feet with TCC and 35 feet with non-TCC were confirmed; pre-operative ultrasonography diagnosed 48 feet with TCC and 36 feet with non-TCC; taking surgery as the gold-standard, the sensitivity, specificity, accuracy, positive-predictive value and negative-predictive value of ultrasound diagnosis of TCC were 87.8%, 85.7%, 86.9%, 89.6%, and 83.3%, respectively. The two were consistent, with κ = 0.732, < 0.001. High-frequency ultrasonography had high diagnostic efficacy for TCC, with an area under the receiver operating characteristic curve of 0.867. The accuracy of ultrasound and CT in the diagnosis of TCC was significantly higher than that of radiograph, and the difference was statistically significant ( < 0.0167). High-frequency ultrasound could also accurately diagnose complications of TCC, such as tibial nerve compression and tendon displacement, while CT and radiograph cannot show these complications. High-frequency ultrasonography can accurately diagnose TCC and its complications, and locate the body surface accurately. Therefore, high-frequency ultrasonography can be used as a routine examination method to supplement CT and provide clinical assistance in precise surgery. This study is the first to use high-frequency ultrasonography to examine TCC and compare its findings with surgical results to explore the diagnostic value of ultrasonography for TCC and its complications.