When a bone breaks, it naturally regrows to heal the fracture. Orthopedic surgeons can help patients with limb length differences by utilizing the body’s ability to regrow bone and some special technology. Limb lengthening works by separating the bone and distracting (stretching) the bone segments. Then, this gradual process allows new bone to grows and fill in the created space.
Limb lengthening can address a variety of conditions
Orthopedic surgeons can help children who have significant differences in their arms or legs with the limb lengthening process. These differences can be from congenital deformities, trauma or previous injuries. A variety of conditions can lead to unequal leg lengths too. For instance, conditions include cerebral palsy, hip diseases, like Perthes disease, and club foot. Sometimes these deformities result in weak muscles or short and tight (spastic) muscles, tendons and ligaments. This irregularity can prevent normal leg growth.
“There are lots of reasons why limb lengthening is a good option for patients,” said Dr. Rachel Randall, pediatric orthopedic surgeon with Marshfield Children’s. “They could have had trauma that affected the growth plates of one of their long bones, and this could be a reason why they have a limb length difference.”
Limb lengthening is a gradual process to allow bones and soft tissues to slowly increase the bone’s length. It can use internal or external fixators, a metal frame that holds bones in place. One internal method for limb lengthening is the Precice tibial nail. This uses a telescoping metal rod, or the lengthening nail, with a magnetic motor. An orthopedic surgeon cuts into the bone to create two separate segments. Then, the surgeon inserts a nail through a small incision into the bone.
After several days to let the healing process begin, the patient uses a special remote to activate the magnet and rod. This external remote control activates the magnetic motor, which causes the Precice nail to slowly lengthen. As the rod lengthens, the bone grows into the space. This new growth increases the length of the arm or leg. Because of the technology, patients can do this at home. Their surgeon will monitor progress and through periodic clinical visits. Depending on the patient, the process of lengthening and then bony consolidation, or strengthening, can take about a year and lengthen a leg up to 8 centimeters.
Follow-up visits continue as your child grows through adulthood
Surgeons will work with the patients and family to determine if the process can be repeated. This communication is key to help patients understand expectations from before the surgery to their follow-up care. “Having an injury or going into surgery is scary for kids and adults,” Randall said. “Part of my job is to prepare patients and families and help manage expectations which also helps during the healing process.”
Throughout this time, patients will have regular X-rays to monitor the progress. Because of this, physical exams are important to ensure a normal range and motion of the joints.
“It’s important to ensure the joints above and below the bone being lengthened are stable and to make sure the soft tissues aren’t developing contractures” Randall said. “Patients can use exercises or physical therapy to prevent this or address any range of motion limitations.”
“We typically have really fantastic outcomes, and kids are really good healers,” Randall said. “It’s rewarding to help them get back to playing outside and doing the things that they love.”