Procedure Promotes Bone Growth And Lengthens A Child’s Shorter Leg
Donna Morris has one thing to say about the limb-lengthening surgery performed to help equalize the length of her son’s legs. “Nobody says it’s going to be easy, but it’s worth it.” Her son Samuel was born with a condition called fibular hemimelia, which would have caused his right leg to be significantly shorter than his left by adulthood.
In April, George Gantsoudes, MD, a pediatric orthopedic surgeon at Riley at IU Health, performed distraction histogenesis, one of several procedures available for treating children with limbs that vary in length—either from growth-plate injuries caused by trauma or infection, or for condition’s like Samuel’s.
“What we’re doing with distraction histogenesis is lengthening a limb by harnessing the body’s natural ability to grow new bone,” says Gantsoudes. It may sound like mad science, but the procedure has been used successfully in the United States since the mid to late 1980s.
It works for the same reason adults can maintain healthy bones by lifting weights. “A bone senses the stress put across it and reforms its own natural, tubular structure,” Gantsoudes says. “It’s the only tissue in the body that’s capable of healing completely without a scar.”
Here’s how the procedure works: Surgeons first add an external fixator—a device that connects pins, drilled into the bone. Afterward, they cut the bone between the two pin segments and attach the pins to a rail with a sliding carriage. After five to seven days of rest and healing, patients carefully turn a screw that adds up to one millimeter of length to the limb each day.
After his surgery, Samuel made four small turns a day for 45 days. That period was followed by 90 days of rest. That gave him 45 millimeters of bone growth in his right leg in a gap created by the cut. Although there was some discomfort after surgery, Morris said her son had no pain during the adjustments.
For each millimeter of added length, patients must be inactive for two days for every day of lengthening, giving the body time to consolidate new bone growth after the process ends. After an appropriate recovery, the new growth is as durable as any other bone.
“We felt Dr. Gantsoudes was really great about choosing the best procedure and the quickest recovery for our son,” she says. The 90-day rest period was a challenge for a seven-year-old boy, but weathering it has already improved his life. Six months after surgery, Samuel just celebrated his eighth birthday and his walking is better. “It has also boosted his confidence and his ability to feel more normal,” she says.
Like many children who are treated for limb length differences, Samuel may need additional procedures to even the length of his limbs by the time he stops growing. Morris hopes those are minor surgeries that won’t be necessary for years, if at all.
Another procedure Gantsoudes sometimes performs to equalize limbs: slowing bone growth in a limb by attaching screws across a growth plate, allowing the shorter limb to catch up. That approach may be less complicated and time consuming than the one performed on Samuel Morris, but it’s not right for every situation. “If we have a patient who is at the end of growth, we have ultimate control of limb length equality,” Gantsoudes says. “We can closely monitor them and stop their growth at any point to achieve our ultimate goal.”