To assess the value of high frequency ultrasound in the diagnosis of injury of the extensor tendon insertion.

A retrospective analysis was performed on 58 patients (aged 5 to 71 years, including 40 males and 18 females) with finger extensor tendon insertion injury confirmed by surgery at the Zhenjiang Medical District of the Eastern Theater General Hospital from July 2015 to June 2019. The characteristics of ultrasound sonograms, ultrasonic diagnostic typing, and the differences of different ultrasound scanning methods in these patients with finger extensor tendon insertion injury were analyzed and compared with the results of X-ray examination.

The ultrasonographic features of injury of the finger extensor tendon insertion showed two types: bone injury and tendon injury. The image features were retraction and thickening of broken ends in 82% of cases, continuous discontinuity in 86%, echo reduction in 77%, avulsion fracture or basal fracture in 36%, and increased break distance by dynamic observation in 70%. Using the surgical results as the golden standard, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of high frequency ultrasound in the diagnosis of bone injury and tendon injury were 84%, 75.7%, 72.4%, 86.2%, and 79.3%, and 90.9%, 72%, 81.1%, 85.7%, and 82.7%, respectively. The differences in the sensitivity, specificity, PPV, NPV, and accuracy of the ultrasound diagnosis versus X-ray diagnosis in assessing bone injury of the finger extensor tendon insertion were not statistically significant (P>0.05). X-ray examination could not diagnose the tendon injury of the finder extensor tendon insertion. The diagnostic coincidence rate between direct ultrasound scan without ultrasound coupling pad and ultrasound scan using ultrasound coupling pad for injury of the extensor tendon insertion was statistically significant (χ²=12.645, P=0.001).

High frequency ultrasound can be used to diagnose and type extensor tendon insertion injury. It is a reliable imaging examination method for extensor tendon insertion injury, which provides a basis for clinical selection of appropriate treatment methods.