Limb Lengthening

What is limb lengthening?

As the name suggests, limb lengthening is a surgical procedure which extends the length of a patient's limbs. It is usually carried out on the legs of individuals who suffer from "Limb Length Discrepancy" (LLD), but it may be carried out for purely cosmetic reasons or as a treatment for injuries.

How does limb lengthening work?

Here’s how a limb lengthening procedure typically works step by step:

1. Osteotomy

Limb lengthening requires an initial surgical procedure called an osteotomy. During an osteotomy, surgeons will make a cut across through bones in the affected limb, and this usually involves either the tibia or fibula when legs are involved.

2. Metal screws are inserted

After the cut has been made, surgeons implant a series of metal screws into the bone, with incisions above and below the cut line. The wound is then closed, and the pins are then attached to the fixator, which is either placed around the leg or inside the bone. This part of the limb lengthening surgery will require a hospital stay of 4-7 days.

3. “Distraction” phase

The osteotomy is followed by a procedure called "distraction", which slowly draws the bone apart, allowing the body to fill the gap with fresh bone tissue - effectively lengthening the limb. This is where the fixator plays a crucial role, moving the bone apart at tiny 0.25mm intervals, usually four times a day.

External vs Internal fixators - External fixators consist of a series of stainless steel rings that are connected to each other by rods and are attached to the bone via high-tension wires. This limits the mobility of the patient during the distraction phase, making crutches a necessity in most cases.

Internal fixators are becoming more common and are also known as intramedullary or PRECICE rods. These PRECICE rods have been designed to be "telescopic", meaning that they can gradually extend, and this extension is achieved via a magnetic device placed above the affected limb.

4. Limb stabilisation

When the desired length has been achieved, that's not the end of the limb lengthening. While the internal or external fixator can now be removed, the limb must be stabilised, often via a plaster cast, and this could take as long as 3-4 months.

A final appointment with surgeons and physicians will be required before patients get the all-clear to resume normal activities.

Are there different types of limb lengthening procedure?

Yes. There are two major types of limb lengthening procedure. The most common is known as the Ilizarov Procedure, which involves an osteotomy followed by the implantation of pins and the use of a fixator to slowly move the bone segments apart. As we've seen, there are also two types of fixator: internal and external.

The other procedure is known as the Wagner Technique and is much less common. This version uses bone grafts and plating to extend the limb more rapidly than in the Ilizarov Procedure, and it therefore requires a greater number of hospital visits.

If both techniques are available, speed could be a factor for your limb lengthening. Studies have found that the Ilizarov Procedure can add 1cm of length in 12 days, while the Wagner Technique achieved the same degree of lengthening in 9 days. However, the same studies also found a greater frequency of complications with the Wagner Technique as well as a longer consolidation phase (as the bone strengthens). So the overall treatment duration can often be similar.

What should I expect from a limb lengthening procedure?

When embarking upon a limb lengthening procedure, you should be ready for rather lengthy periods of inactivity and impaired mobility as well as a long treatment duration. The separation and distraction of limb bones is a gradual process, and it is essential to ensure that the procedure is carried out properly to avoid deformities or failure. This is why it is important that you find a surgeon who is board-certified and who has a solid experience with limb lengthening surgery.

While the surgery itself is carried out under anaesthetic, patients may also experience some pain along the way. This could be via tightening of soft tissues in the affected limb or stiffness in the joints. The fixator itself should not cause pain.

Mental health complications could be considered a more serious issue than the physical pain caused. For some people, being confined to a set of Ilizarov rings for three months or more can lead to depression or pathologies like weight gain. So, patients should prepare for a difficult period of inactivity. Good clinics and hospitals are well aware of these risks, and psychological care should be part of the aftercare process.