Dorsal Screw Penetration With the Use of Volar Plating of Distal Radius Fractures: How Can You Best Detect?

Objectives: To evaluate the most vulnerable position at which volar plate screws may penetrate the dorsal cortex of the radius and to determine which specific intraoperative fluoroscopic images (lateral, 45 degrees supination, 45 degrees pronation, and dorsal tangential) are most useful to detect dorsal cortex penetration.

Methods: Four 2.5-mm locking screws were inserted distally using 18-, 20-, or 22-mm screws in 7 cadaveric specimens apiece. The specimens were then evaluated to count the number of screws breaching the dorsal cortex and the amount of penetration. Lateral, 45 degrees supination, 45 degrees pronation, and dorsal tangential fluoroscopic views were taken of each wrist. Sixty-three orthopaedic surgeons of varying experience were then asked to evaluate whether the screws penetrated the dorsal cortex after viewing each image.

Results: Dorsal cortex screw penetration of at least 1 screw occurred in 3.6% of specimens with 18-mm screws, 25% of specimens with 20-mm screws, and 57% specimens with 22-mm screws. Radial-sided screws more commonly breached the dorsal cortex. The sensitivity was 58% on the lateral view, 88% on the 45 degrees supination view, 53% on the 45 degrees pronation view, and 67% on the dorsal tangential view. Additionally, surgeons with more experience were less accurate in detecting prominent screws.

Conclusions: Clinicians should consider use of these views to evaluate dorsal screw penetration after volar plating but may opt to subtract a few millimeters from their measured screw lengths to avoid over penetration past the dorsal cortex.