Our 10-year-old son has had Blount disease since he was four. He’s had numerous surgeries that have helped but haven’t corrected the problem. Now they want to put a special external fixation device on him that he can adjust himself. I guess it’s just the turn of a screw three or four times a day. Doesn’t 10 seem too young to be in charge of this by himself?

You may be referring to the Multi-axial Correction (MAC) device made by the Biomet company. This external fixation system is able to make corrections in the angle of the bone from two separate angles and two separate planes of translation. It also corrects bone length and bone rotation.

That’s a lot for one fixator device to accomplish. Not only that, but as you will find out, it is easy to adjust (or monitor). The screws are turned one at a time, four times each day until the desired results are achieved. Usually this means the bone has lengthened enough to equal the other leg or the deformity is corrected (sometimes both).

Parental supervision may be all that’s required. The surgeon will instruct you and your child on what to do, how to do it, and what to expect. Periodic X-rays will be taken from a variety of angles to assess progress and make any corrections necessary.

This particular device has a secondary hinge that prevents additional deformities from occurring should the device be put on incorrectly. Unlike other devices, this feature makes it possible to correct the problem without going back into surgery. Surgeons say the advantages outweigh the disadvantages.