Limb Lengthening Surgery

Limb lengthening uses the body's own ability to make bone. The bone is divided, a device holds the two ends, and the gap between them is widened very slowly — about one millimetre a day — so new bone forms in the space while nerves, vessels, muscle and skin stretch to keep pace. Going faster than the tissue can follow is what causes the complications, which is why the rate is fixed and slow.

Who it is for

Leg length differences from birth defects, damage to a growth plate in childhood, a fracture that healed crooked or failed to heal at all, skeletal dysplasias and bone disease, and conditions such as polio, cerebral palsy and Perthes disease. Patients between about eighteen and twenty-five, whose bones have finished growing, are the more usual candidates.

The two methods

An external fixator is a frame outside the limb, attached through pins, wires or screws, and adjusted from outside. An internal lengthening nail sits inside the marrow cavity and is driven by a magnet held against the skin, so nothing crosses it. The choice depends on the bone, the amount of lengthening and the deformity being corrected.

The phases, and how long they really take

A latency period of about a week after surgery lets a protective callus form before any lengthening begins. Then comes distraction at a millimetre a day until the target is reached. Then consolidation, with the device still in place for several months while the new bone hardens — roughly six weeks of healing for every centimetre gained. Crutches, a walker or a wheelchair are needed for about six to eight weeks after surgery, and hospital admission is at least three days, with mobility therapy during the stay and regular visits afterwards to adjust the device.

Risks, and the honest arithmetic

Infection — particularly around external pins, which must be kept scrupulously clean — bone that heals too quickly or too slowly, joint stiffness, swelling, and contractures where muscle, tendon or skin tighten permanently. Sources quote success rates for this operation that contradict each other outright, so we quote none: ask your surgeon how many of these they do each year, what their own complication rate is, and how many patients needed an additional procedure. Those three answers are worth more than any published percentage.

What we arrange around it

This is the longest commitment on this page by a wide margin. The lengthening and consolidation run for months, much of it away from the hospital, so we plan the stay around surgery and the early adjustments, and set out in writing what has to continue at home and who checks it.