The role of ultrasonography in diagnosing acute closed volar plate injury of proximal interphalangeal joint.

BACKGROUND

Acute closed volar plate injury of the proximal interphalangeal joint (PIP) is a common hand injury. In the past, there were few objective evaluation imaging methods for the degree of volar plate injury. The purpose of this study was to investigate the role of high frequency ultrasonography in diagnosing volar plate injury, and to explore whether ultrasound can provide a beneficial guidance to clinical decision-making and appropriate treatment adopting through accurate US classification of volar plate injury.

METHODS

From May 2019 to may 2022, 41 patients diagnosed with volar plate injury were included in this study. All patients underwent ultrasonography and X-ray examinations. The sonographic features were analyzed. A new kind of classification of volar plate injury based on ultrasonography findings was described.

RESULTS

Either an injury of volar plate or an avulsion fracture of middle phalangeal base was identified clearly on ultrasonography, according to which volar plate injury could be divided into three types: A, B and C. Type A, avulsion fracture of the middle phalangeal base without volar plate rupture; Type B, full thickness tear of the volar plate without avulsion fracture; Type C, partial thickness tear of the volar plate. The average thickness of the three types of injured volar plate measured by ultrasound was 0.33 ± 0.05 cm, and the average thickness of the volar plate at the same site of the corresponding finger on the contralateral side was 0.22 ± 0.03 cm. There was significant difference between the two group (t = 11.823, p = 1.2476 *10^(-14)).

CONCLUSIONS

High frequency ultrasonography could be a reliable, accurate, convenient and non-radioactive diagnostic imaging technique in the evaluation of acute closed volar plate injury of PIP. And ultrasound could provide a beneficial guidance to clinical decision-making and appropriate treatment adopting through accurate US classification.