Part of the confusion with this fracture pattern is the various terms used to describe these fractures. In addition to transverse, complete, and bicortical, some clinicians may call them non-buckle fractures. Some orthopedic surgeons and radiologists might call these greenstick fractures, while others would argue that is incorrect since a greenstick fracture breaks on the convex/distracted side but these fractures occur on the concave/compressed side.
While it’s easy to understand the confusion, it is important to recognize that, whatever the label, these fractures can be subtle on X-ray, are more likely to shift, and require well-molded immobilization. Fractures tend to shift in the direction the original force was applied. When falling on an outstretched arm, the force is applied to the distal fragment in a volar-to-dorsal direction, so the fracture tends to drift dorsally. To discourage this tendency, molding should be in the opposite direction in flexion. Since molding is important, plaster is preferred over fiberglass. Plaster has inherently better molding properties (reference: pretty much every orthopedic textbook!). A radial gutter splint (with connected plaster on both the dorsal and volar sides of the radius) that is properly applied and molded in flexion works very well. Follow-up should be arranged within a week with orthopedics since X-rays often will be repeated to check alignment for these potentially unstable fractures.
Finally, the last case (Case 4) involves the most common ED molding mistake seen in our fracture clinic: failure to recognize the volar buckle fracture. In these cases, the distal radius fracture tends to shift volarly. A helpful tip: When looking at the lateral wrist X-ray, always identify the thumb first as this defines the volar side of the forearm. If a buckle is seen on the volar cortex, the force must have come in the dorsal-to-volar direction, and when asked, patients often report a fall on the back of their hand, not on their outstretched arm. If such fractures shift, they shift volarly, so molding must be in the opposite direction in extension.
A safe approach for pediatric volar-based buckle fractures of the distal radius, particularly if there is any volar angulation of the distal fragment, is to mold them into extension. Again, if molding is important, plaster is preferred over fiberglass. A well-molded radial gutter splint molded in extension (optional to extend above the elbow) with orthopedic follow-up within a week is recommended.
A Final Point
The radiology report of each of the above four cases may read, “buckle fracture of the distal radius.” Radiologists are not necessarily aware of these subtle yet clinically relevant X-ray differences. Errors will occur if we, as emergency physicians, rely solely on the radiologist’s report. We must review the images ourselves, not just read the report!