Our daughter had surgery to correct a leg length difference. After months in a fixator cage around her leg, it was finally removed. The clinical exam and X-rays show she may have been overcorrected. She had X-rays taken all along. Why didn’t this show up sooner?

The accuracy and reliability of X-rays during limb lengthening procedures has come under question. A study was recently published pointing out the problems surgeons face when relying on X-rays to guide treatment of this problem.

The researchers found that there is a tendency for the knee to rotate outwardly when the leg is in the external fixator. This change in alignment affects the angles measured and information from the X-rays used to calculate correction with the fixator. Not only that, but they also noticed the malalignment in the fixator resulted in differences observed in the leg that wasn’t in the fixator.

Overcorrection or undercorrection may occur as a result. This is the first report of this type made available to surgeons. It may be that taking the X-ray with the knee carefully positioned with the patella (kneecap) facing forward will take care of the problem.

In the future, improved computer technology used to assess X-rays may also help provide a more accurate picture of what’s needed for a perfect surgical result.