The article, “Guiding Femoral Rotational Growth in an Animal Model” by Arami, et al. is an intriguing variation on the common applications of guided growth in pediatric patients. Implants that bridge the physis to inhibit growth in a given anatomic location are widely used to correct angular deformity or leg-length differences in the growing child and to decrease the need for a more invasive corrective osteotomy.
At present, correction of rotational deformity in the pediatric femur or tibia requires a derotational osteotomy and commonly six weeks of casting postoperatively. This study in rabbits demonstrates the ability of implants to alter the rotational profile in the growing femur by bridging the physis in an oblique orientation, rather than in a vertical orientation used for angular deformity correction.
The authors have elegantly demonstrated histologically the swirling or bending appearance of the physeal columns in treated femora, while controls maintained the normal linear columnar appearance of the physis. This interesting and unique animal study lays the foundation for consideration of using oblique placement of physeal-bridging implants to guide rotational growth in skeletally immature patients, without the need for osteotomy.