gms | German Medical Science

Objectives/Interrogation: This novel radiological protocol allows temporal imaging of a cross section of the DRUJ with movement of the forearm from pronation to supination. The aim of this study was to optimise the imaging for 4D CT scanning in investigating instability of the DRUJ and describe the displacement of the ulnar head at the sigmoid notch with movement and time.

Methods: This was a prospective study. Adult patients with acute or chronic symptoms and signs of DRUJ instability presenting to our Institution from 2017 were included. Patients were identified in the outpatient clinic. Clinical information was gathered using the electronic health records. The imaging was viewed on PACS and the 4D viewer on the Osirix system. The point of maximal displacement of the ulnar head from the sigmoid notch was identified and measured using a modification of the radioulnar ratio method. The results were analysed on a spreadsheet.

Results and Conclusions: The optimal radiological protocol is described. The patient demographics and clinical presentation of six patients are described. The maximal radioulnar ratio for each patient is currently being analysed and will be presented. The degree of displacement at the sigmoid notch with time, from supination to pronation is also described. This is compared to the unaffected side. The clinical utility of this imaging modality is discussed.

Patients with instability at the DRUJ present a diagnostic and management challenge. Using this novel protocol, 4D CT scanning of these patients allows a much improved understanding of the degree of instability at the DRUJ with movement and time. This is shown to aid in clinical decision making. Further studies using this protocol in investigating the variety of patterns in DRUJ instability are warranted.