Abstract
BACKGROUND: The accurate evaluation of Narakas type IV obstetrical brachial plexus palsy (OBPP) has been limited due to certain shortcomings in imaging technology. High-frequency ultrasonography may offer clearer observation of the brachial plexus, providing a more reliable imaging method in diagnosis and treatment for children with Narakas type IV OBPP. This study aimed to investigate the role of high-frequency ultrasound technology in assessing the location and injury characteristics of nerve root lesions in children with Narakas type IV OBPP. METHODS: A total of 24 patients underwent brachial plexus reconstruction at the Children's Hospital of Fudan University between December 2020 and November 2021 after ultrasound examination. Ultrasound exploration of the bilateral brachial plexus roots of all patients was performed with an ACUSON Sequoia ultrasound system by a single sonologist before ultrasound results were compared with findings from intraoperative exploration. RESULTS: A total of 24 out of 27 patients who sought medical attention underwent an operation before an ultrasound examination. Among the 24 patients, nerve trunk injuries identified by ultrasonography were classified into two categories based on the distance from the intervertebral foramen: (I) abnormality beside the intervertebral foramen, suggesting the presence of nerve root avulsion injury, and (II) postganglionic abnormality, suggesting the presence of postganglionic nerve root rupture. All injuries of the C5-7 nerves could be observed by ultrasound, whose accuracy in diagnosing the injury to the C5, C6, and C7 nerves was 83.3%, 75.0%, and 75.0%, respectively. The detection rate for ultrasound of C8 nerve injury was 37.0%, but the accuracy of ultrasound in 10 patients was 100%. CONCLUSIONS: High-frequency ultrasonography clearly showed the course, lesion locations, and injury characteristics of the C5-C7 nerve roots with a relatively high accuracy, but was limited in examining the C8 and T1 nerve roots.