Science-- there's something for everyone

Sunday, May 20, 2012

A magnetically controlled growing rod for treating scoliosis

Scoliosis is a disorder which causes the spine to curve sideways. In severe cases, it must be corrected surgically by attaching rods to straighten the spine. Unfortunately, as treatment often occurs during childhood, using fixed bracing rods can prevent normal spinal growth. Extendable rods are a big improvement, but they require surgical procedures every few months to mechanically lengthen them. Kenneth Man-Chee Cheung and his colleagues from the University of Hong Kong had a better idea. They used magnetically controlled growing rods (MCGR) to treat their young patients.

MCGRs are surgical rods that contain an extendable region with an internal magnet. The researchers implanted the MCGRs into five patients, all of whom were still actively growing. Each child was reevaluated every month, during which his or her rod was nonsurgically extended using an external magnet. Thus far, two of the patients have been observed for a full two years. The technique compares favorably with traditional growing rods but has several advantages. First, MCGRs do not require surgical procedures to extend them, greatly reducing the risk of infection, not to mention the pain of additional surgeries. Second, because extensions can occur much more frequently (doctors are loathe to operate on children more than twice a year), normal spinal growth can be much more closely approximated.

Needless to say, a sample size of two doth not a scientific consensus make. However, the preliminary results suggest that this technique is well worth further study. By the way, this is not the first time magnetic prosthetics have been used. Two years ago, I wrote about a similar technique used to lengthen a little girl’s leg.