Biological mechanisms of leg lengthening technique
The biological mechanisms of leg lengthening surgery are based on tension-stress theory proposed by Ilizarov in 1980s. Under gradual mechanical traction, cells in the musculoskeletal tissues are activated in terms of cell proliferation and differentiation, angiogenesis is also very active, as a result new callus are formed during lengthening. This process is like a continuous fracture healing accompanied by rapid bone remodelling. Some scholars suggested that leg lengthening resembles the embryonic bone development.
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Left Figure:Showing the new bone formation occurring in the lengthening gap |  |
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| Right Figure: Scanning electronic microscopy showing that the new bone structures (upper arrow) are identical to the intact bone structures (lower arrow). | |||||||
Some scholars have also studied the effect of tension stress on nerves, blood vessels and muscles, it was concluded that all of these tissues, like bone tissue, can be promoted to grow and regenerate during leg lengthening process. The most commonly used lengthening rate is 1mm/day in several steps. For an overview on the new development on the biological mechanisms of leg lengthening (distraction osteogenesis), please see Dr. Gang Li’s recent review article on “New developments and insights learned from distraction osteogenesis”.
In conclusion, when leg lengthening surgery was performed in accordance with the tension stress laws, and under appropriate mechanical conditions, it will promote musculoskeletal tissue and cells to proliferate and grow. The cellular structures, biological characters and functions of the newly formed tissues are more or less the same as the original skeletal tissues. The only difference is that leg lengthening is a surgical procedure, and usually is limited to low limbs, with some scars (cuts and pinholes) on the skin, which can be removed later through cosmetic surgery if necessary.
