by J. Andrew Bowe, MD
J. Andrew Bowe, MD, is assistant clinical professor, department of surgery, Robert Wood Johnson University Hospital, New Brunswick, N.J.
The treatment of pediatric forearm fractures traditionally has been conservative with closed reduction and casting. I was trained that younger children treated with a closed reduction and casting routinely had good to excellent results and this was based on the supposition that residual angulation and malrotation remodels with subsequent growth. This remodeling is more likely in distal fractures, especially in the lateral plane as opposed to the AP plane. In adolescents close to skeletal maturity, the treatment is similar to adult forearm fractures with open reduction and internal fixation with compression plating.
But not all children end up with good results. It has been my experience that some children lose forearm rotation and function, while others can end up with a painful, unstable distal radial ulnar joint. Angulation, rotation, encroachment on the interosseous space, displacement, and length discrepancy are not always predictable indicators of loss of motion. There also is recent literature about corrective osteotomies secondary to malunited forearm fractures. Interestingly, a high percentage of these patients who required corrective osteotomies were treated as children less than 13 years of age with closed reductions of forearm fractures. This operation is technically demanding with a fairly high incidence of complications. In addition, this study showed that corrective osteotomy for post-traumatic forearm fractures gave much better results if done early within 12 months. Thus, watchful waiting to see improvement with growth may compromise successful corrective osteotomy.
The question therefore arises, which group of patients is going to have a bad result and what can be done about it? In almost all closed forearm fractures in children under age 8, I continue to perform a closed reduction and casting. I accept the best reduction attainable. At this age, significant angulation and malrotation can probably be accepted because of subsequent growth and the results seem to be uniformly good. I treat older teenage children, closer to skeletal maturity, as adults with ORIF with compression plating. However, in the 8- to 14-year-old group, I have become more aggressive. I will try a closed reduction, however, if this fails, a closed or open reduction with IM fixation of the ulna or radius is my next treatment. The indications are in evolution but include:
I prefer IM rods or pins (Kirschner wires or Rush rods). I have found that a reduction of the ulna can be readily achieved and a percutaneous IM rodding can be performed. The entry site is through a small incision proximally about the olecranon apophysis, stopping the rod before the distal ulnar physis. The Kirschner wire or pin is bent over and left outside the skin. Once the ulna has been aligned and stabilized, a closed reduction of the radius is frequently easier and stable. Only if the radius is grossly unstable would I consider an IM pin or rod of the radius as well.
If it is necessary to open the fracture site, less exposure is required with the IM technique compared to plating. I believe that single bone (ulna) fixation followed by a closed reduction of the radius and a long-arm cast is sufficient in the majority of cases and recent literature support this.
There are many advantages of IM pinning. It minimizes angulation in malrotation. It usually can be performed percutaneously without opening the fracture site. It is ideal in younger children where plates are frequently too large for the diameter of the mid-shaft of the radius and ulna. Finally, the removal of the hardware is easier and safer, and many times can be done in the office. One disadvantage is that casting is still required, however, this is rarely a problem in children.
In summary, the vast majority of pediatric forearm fractures can and should still be treated with closed reduction and casting. Nevertheless, malunion of forearm fractures can lead to functional problems, and corrective osteotomy is not a benign or simple procedure. Therefore, if indicated, a very acceptable treatment modality is a closed or open reduction and IM rodding. This technique is safe, effective and produces excellent results.