What Is Limb Lengthening?

Limb lengthening is a surgical procedure used to lengthen bones, replace missing bone or correct deformities in bone structure. The surgical technique used in our hospital for limb lengthening was originally developed by Dr. Gavril A. Ilizarov in Russia in 1951. In a limb lengthening procedure, doctors attach an external frame to the affected limb. The structure supports the limb while growth is encouraged at the site of a fracture created during surgery. Doctors can now safely lengthen bones up to six inches. More than one stage of treatment may be required for extensive limb deformities or shortening.

Limb Lengthening and TSRHC

Physicians at Texas Scottish Rite Hospital for Children developed the TRUE/LOK External Fixation System, a modification of Ilizarov's frame, to treat patients with a variety of limb length discrepancies. The TRUE/LOK system requires a less complicated surgical procedure and allows for greater patient comfort during the lengthening process. The patented TRUE/LOK system is now used around the world and continues to be improved through the efforts of the Center for Excellence in Limb Lengthening and Reconstruction at TSRHC.


Limb length discrepancies, also known as limb length differences, can be present at birth or may develop during childhood.

Limb length discrepancies, also known as limb length differences, can be present at birth or may develop during childhood. Certain birth defects can result in one limb being underdeveloped and shorter than the other. Severe bone infections can cause one limb to grow at a different rate than the other. Traumatic injuries can also cause one limb or bone to grow slower than the others. Neurological disorders, such as cerebral palsy or spina bifida, can also result in limb length discrepancies.

A doctor can determine the severity of a limb length discrepancy by taking measurements or examining X-rays.

This evaluation is often repeated, sometimes every six months, to monitor the limb length difference in growing children.

Many patients with limb length differences require no treatment.

Often the difference in length is so slight it does not cause pain or difficulty in functioning. When a limb length difference is greater than one inch, surgery may be required. When a limb is to be lengthened, an external fixation system, such as the TRUE/LOK™ system, is placed on the affected limb to allow for growth in the limb and serve as a support while the developing bone strengthens.

One alternative treatment method, which may be used for more minor limb length differences, is to “slow” growth in the longer limb with surgery. This treatment is performed during a child’s growing years.