Intraoperative assessment of the dorsoulnar fragment reduction and fixation with extended tangential view: A study of diagnostic accuracy

The study aimed to evaluate the reliability of the intraoperative extended tangential view (ETV) in assessing the reduction and fixation of the dorsoulnar fragment (DUF) during the treatment of comminuted distal radius fractures (DRFs) with volar plates. A retrospective review included 26 patients who underwent open reduction and volar locking plate internal fixation for AO C3-type DRFs with DUF between March 2023 and January 2024. Each patient received intraoperative ETV fluoroscopy and immediate postoperative wrist CT scans. DUF reduction quality was classified simply as excellent (anatomical reduction), good (<2 mm residual displacement), or poor (> 2 mm displacement). Both reduction quality and screw position relative to DUF were independently evaluated through fluoroscopy and CT. The study found consistent results across both methods: 23 reductions were excellent, 2 were good, and 1 was poor. The screw's mean distance to the distal radioulnar joint was 6.19 ± 2.76 mm on ETV compared to 4.21 ± 2.05 mm on CT, with a Pearson correlation of 0.925 (P < .05). The screw tip's distance to the dorsal cortex measured 3.69 ± 1.08 mm on ETV versus and 2.72 ± 1.01 mm on CT, with a correlation of 0.937 (P < .05). When compared to the postoperative CT evaluation, which was deemed the gold standard, the intraoperative ETV measurements displayed excellent accuracy and substantial relevance to the CT findings. The study suggests that the intraoperative ETV is a valuable tool for assessing the reduction and fixation quality of the DUF in comminuted DRFs. Level IV, retrospective case series.