Magnetically-controlled "growing rods" promise less surgery for children with scoliosis
By Ben Coxworth
April 23, 2012
Scoliosis is a lateral deformity of the spine, that most often shows up in young children and adolescents. Besides resulting in disfigurement, in some cases it can also cause breathing problems. In severe cases, if the child is still growing, telescoping steel rods are surgically implanted alongside the deformed section of the spine, in order to straighten it. Unfortunately, repeat surgeries are necessary every six months, in order to lengthen the rods as the child grows. Now, however, scientists from the University of Hong Kong are reporting success in the first human trials of a system that incorporates rods which can be lengthened using magnets instead of surgery.
As its name suggests, the magnetically-controlled growing rod (MCGR) system uses magnets held outside of the body to engage and then extend the ends of the implanted rods. This can be done relatively quickly in a non-invasive outpatient procedure. The surgery required for the lengthening of traditional rods (a process known as a “distraction”), by contrast, requires hospitalization and general anesthesia. Not only is this unpleasant for the children, but it also causes them to miss school, involves considerable medical expenses, and often also requires at least one parent to miss work while the child recuperates.
In the recent trials, MCGRs were implanted in five test subjects. Once every month since, those subjects have been going into a clinic to get those rods lengthened. Two of the patients are now at the 24 month-mark of their treatment. The mean degree of their spinal deformities was 67º before implantation, but is now down to 29º. Their spines have grown at a normal rate, and they have reported no pain or other problems throughout the process.
“Whether MCGR leads to significantly better outcomes than traditional growing rods is not yet known, but early results are positive and the avoidance of open distractions is a great improvement,” the scientists said in a report on their research. “Additionally, this new growing rod system has potentially widespread applications in other disorders that could benefit from a non-invasive procedure to correct abnormalities. MCGR could assist with correction of limb abnormalities, thoracic insufficiency syndrome, limb lengthening, limb salvage procedures, or any disorders or injuries in which slow, progressive change to bone structures is needed.”