Abstract
BACKGROUND: Open reduction and internal fixation have been frequently applied for displaced midshaft clavicular fracture. Plate and screw fixation of clavicular fractures could provide rigid fixation and rotational control. Proper implant positioning in surgical fixation is critical to prevent iatrogenic complications. Fluoroscopy plays an important role in the intraoperative evaluation of implants. This study aimed to introduce a new fluoroscopic projection to evaluate the positioning of plates and screws. METHODS: Adult patients with a diagnosis of acute displaced midshaft clavicular fracture were included in this study. The slope angle of the midshaft clavicle was measured on sagittal reconstructions of preoperative computed tomography (CT) scans. The incidence of screw revision based on intraoperative standard posteroanterior (PA) and PA 25° cephalic skyline projections was compared. The interobserver agreement for the two projections was calculated. RESULTS: Twenty-nine patients with midshaft clavicular fractures were enrolled from January 2020 to June 2021. The PA 25° skyline projection could clearly display the tangential line of the plate and inferior border of the clavicle. The slope angle on the superior surface of the midshaft clavicle was 26.0 ± 5.8° (range: 18.5-38.3°). The incidence of screw revision using the PA projection (72.4%) was significantly different from that using the PA 25° skyline projection (34.5%) (P < 0.05). The concordance of the screw revision rate based on the standard PA and PA 25° skyline projections was strong, with kappa coefficients of 0.680 (95% CI: 0.394-0.968) and 0.776 (95% CI: 0.537-0.998). CONCLUSION: The PA 25° skyline projection corresponds to the slope angle of the midshaft clavicle. It can provide more accurate information regarding the proper screw length and be applied as a routine method for intraoperative evaluation.