Is ultrasound superior to fluoroscopy in distal radius volar fixation?

OBJECTIVES

In volar distal radius fixation, conventional and additional fluoroscopic views could not be sufficient to assess dorsal screw penetration. Ultrasound (US) has been suggested as a technique to improve this assessment. The objective was to determine the agreement between these two explorations in a clinical study. Quantify time-consuming of intraoperative US was the secondary objective.

MATERIAL AND METHODS

A prospective descriptive study was performed. Thirty patients with a surgical distal radius fracture were treated with volar fixation by five consultant surgeons in a level I Trauma Centre. Final intraoperative fluoroscopic views: AP, lateral, 20º tilted lateral and Dorsal Tangential views (DTV) were performed assessing for dorsal screw protrusion. Then, ultrasound was performed to reassess dorsal cortex integrity. Those protruding screws were registered and changed.

RESULTS

A total of 153 screws were examined. Four protruding screws were observed with no multiple protruding screws in the same fixation. Intraoperative ultrasound detected a dorsal screw protrusion in one fixation, assessed as correct by radiological projections. Almost perfect agreement was found between DTV and US examination k = 0.83 (p < 0.001). The mean surgical time was 63 ± 20.3 min while the addition of the ultrasound, supposed an average of 4 ± 1 min more.

CONCLUSION

Ultrasound did not show a clinically significant improvement in the assessment dorsal screw penetration in distal radius fixation. A high agreement was observed between US and the described fluoroscopic views. The addition of intraoperative US was a non-significant time-consuming procedure.

3D virtual pre-operative planning may reduce the incidence of dorsal screw penetration in volar plating of intra-articular distal radius fractures

Purpose

To evaluate the effect of three-dimensional virtual pre-operative planning (3DVP) on the incidence of dorsal screw penetration after volar plating of distal radius fractures.

Methods

A cross-sectional diagnostic imaging study was performed. Twenty out of 50 patients were randomly selected from our index prospective cohort (IPC): a prior study evaluating dorsal tangential views (DTVs) in reducing dorsal screw penetration in internal fixation of intra-articular distal radius fractures using post-operative CT scans to quantify screw protrusion. Pre-operative CTs from this cohort were now used for 3DVP by three experienced orthopaedic trauma surgeons (supplementary video). 3DVP was compared with the corresponding post-operative CT for assessing screw lengths and incidence of dorsal penetration. The Wilcoxon Signed Ranks test was used to compare screw lengths and the Fishers’ exact for incidence of penetration.

Results

Three surgeons performed 3DVP for 20 distal radius fractures and virtually applied 60 volar plates and 273 screws. Median screw length was shorter in the 3DVP when compared to IPC: 18 mm (range, 12–22) versus 20 mm (range, 14–26) (p < 0.001). The number of penetrating screws was 5% (13/273 screws) in the 3DVP group compared to 11% (10/91 screws) in the IPC (p = 0.047). Corresponding to a reduction in incidence of at least one dorsally penetrating screw in 40% of patients in the IPC group, to 18% in the 3DVP group (p = 0.069).

Conclusion

Three-Dimensional Virtual Pre-Operative Planning (3DVP) may reduce the incidence of dorsally penetrating screws in patients treated with volar plating for intra-articular distal radius fractures.

Level of evidence

II, diagnostic imaging study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01800-2.

Influence of training on dorsal tangential radiographic view to detect screw protrusion after anterior plating of the distal radius: a cadaveric study

In this cadaveric study of anterior plating of the distal radius, we aimed to determine the interobserver agreement and diagnostic performance for detecting dorsally protruding screws using the dorsal tangential radiographic view before and after specific training. Without prior instruction, 13 observers interpreted the dorsal tangential view of cadaveric specimens, in which anterior radial plates were placed. After seeing a training video on the dorsal tangential view, they repeated the task. Though we found that accuracy and interobserver agreement was lower than described in some other clinical series, training led to statistically significant improvements of (1) the interobserver agreement on the decision to exchange screws, (2) the self-confidence of the surgeon in obtaining adequate views, and (3) the number of fluoroscopic images required to obtain these views. After training, the number of protruding screws missed was reduced by 36%, but 7% of dorsally protruding screws was still missed.