Limb Lengthening

The limb lengthening process works by gradually growing new bone and soft tissues (skin, muscle, nerves, blood vessels, etc). This new growth is called tissue regeneration. Bone and soft tissue regenerate when they are distracted (pulled apart) at a very slow rate of approximately 1 mm per day. If the rate of distraction is faster than this, bone may fail to form between the two ends of the bone that are being pulled apart and soft tissues, such as muscle, may experience contracture (get too tight) or nerves may become paralyzed. If the rate of distraction is too slow, premature consolidation may occur (the bone may consolidate too soon), preventing the lengthening device from further pulling it apart. The lengthening devices used could be external fixators or those that are fully implanted inside the bone.

There are two phases of lengthening until the bone is fully healed : the distraction phase and the consolidation phase. The former is the lengthening phase. After the desired length is obtained, the newly regenerated bone is still very weak because of lack of calcium within it. The hardening and calcification of this new bone is called the consolidation phase.