One can only begin to imagine the problems facing a child with one leg that’s visibly shorter than the other. It’s not as rare as one might think. In fact, it’s one of the most common conditions prompting a visit to a pediatric orthopedic surgeon.
Sometimes a child is born with a shorter leg. It can also happen from an illness or injury. Fortunately, modern treatments to equalize leg lengths can enable a child to run, climb, play and lead a happy life.
"We are in a golden age of pediatric orthopedics, and some of the most dramatic advances have occurred in the field of limb lengthening and the correction of bone deformities,” said Dr. Roger Widmann, Chief of Pediatric Orthopedic Surgery at HSS.
The latest advance is a magnetic lengthening rod that is implanted into the shorter bone to make it longer. An external magnet applied to the skin several times a day painlessly elongates the rod – and the bone – in very small increments until the desired leg length is reached.
When you look back at the earliest attempts to correct this orthopedic problem, you see the extraordinary progress that’s been made. “Surgical procedures to achieve limb lengthening in the 19th and early 20th century had inconsistent results and high rates of complications, including deformity, infection and long periods of immobility,” said Dr. Widmann.
Still, the early pioneers played an important role in the evolution of limb lengthening procedures. Many of the advances we see today were built upon their efforts.
In the 1950s, a Russian physician named Gavriil Ilizarov would revolutionize the field. Dr. Ilizarov came up with a brilliant invention that combined biology and biomechanics. His device, known as a circular external fixator, ushered in the modern era of limb lengthening surgery. The fixator was a metal frame that wrapped around the leg externally. It was attached to the bone through the skin with wires.
Key to the method was Dr. Ilizarov’s discovery that the body has the ability to form new bone under the right conditions. His procedure, still used today, entails making a delicate cut in the patient’s bone while preserving its blood supply. The external fixator stabilizes the limb, and then a very gradual elongation of the frame slowly lengthens the bone and creates conditions for the body to fill in the gap with new bone.
“His circular fixator was extraordinarily flexible, customizable and modifiable,” Dr. Widmann explains. “And his technique could be used for a wide variety of orthopedic problems: to make a leg longer, to correct a bone deformity, or to repair a bone that failed to heal after a fracture.”
Dr. Widmann notes that the Ilizarov technique is still widely used, and modifications over the years have enabled surgeons to attach the frame to the leg more comfortably.
The Taylor Spatial Frame represents another innovation in external fixation. It utilizes computerized guidance and a redesigned frame, allowing for a more flexible and more efficient correction of deformities, according to Dr. Widmann.
The most recent advance, magnetic limb lengthening rods, are placed inside of the patient’s shorter bone through a small incision. So, unlike the external frames, they’re invisible from the outside. Lengthening is performed several times a day utilizing an external electromagnet.
“For many bone length problems, the magnetic lengthening devices have cosmetic advantages over the external frames, and the results of lengthening have been excellent,” explains Dr. Widmann. “Both the Ilizarov technique utilizing computer guidance and the magnetic lengthening rod represent amazing new technology that improves the care of children with leg length discrepancies and limb deformities.”