There are two types of leg lengthening that all prospective patients have the option of choosing from: External Methods and Internal Methods. External methods are comprised of a metal fixator on the outside of the leg whereby distraction is caused by bolts on a screw that are turned to produce lengthening. Internal methods are comprised of intramedullary devices (IM) that are placed inside the bone canal and all distraction takes place inside the leg.The most common External Methods are:
This is the 'original' form of leg lengthening, pioneered by Russian physician Gavril Abramovich Ilizarov in the 1950s. Most external techniques are based on this method. Typically, the tibia and fibula bones of both lower legs are broken and an external fixator device is attached to each half of each severed bone. The device is attached to the bones using pins or wires that go through small holes drilled through the patient's skin.
This device has screws which are then turned to stretch the bones at a very slow rate whilst the bone grows into the space between the breaks. This part is called "distraction" and is done at varying rates of up to 1mm per day. At the end of the distraction phase, the bone is then left to strengthen and "consolidate". This can take anything from three months to one year and care must be taken not to break the bone before it is at full strength. After consolidation, the bone is as strong as the original, but longer.
Some modern practitioners consider this approach to be barbaric, and the requirement for multiple pins through the skin into the bones can be painful, and also lead to infections and other problems. However, this is often the cheapest approach and has a long track-record of success. It is practiced in many different countries and clinics.
Diagram showing Ilizarov Apparatus:
LATN and LON are methods whereby lengthening is done with an external ring fixator, but then an internal IM rod is fixed inside the bone to speed up the time frame for returning to normal.
LENGHTENING AND THEN NAILING (LATN)
This is a new combination of internal and external methods that involves both an external fixator and an internal ?nail?, which is inserted after the external frame has been removed.
The procedures starts in the same was the traditional Ilizarov approach, but after lengthening, the external frame is removed and a stainless steel rod inserted into the bone. This rod or ?nail? provides stability and protects the bone as it consolidates.
It is claimed that this approach reduces the time required for consolidation, allowing a patient to return to their normal life much more quickly than in the standard external-only method.
Clinical studies have also shown that this approach also has the advantage over the similar Lengthening over Nails (LON) approach, in that there is a reduced risk of infection as the internal and external devices are not used at the same time.
LENGTHENING OVER NAILS (LON)
This is a combination of internal and external methods that involves both an external fixator and an internal ?nail? used simultaneously.
Lengthening Over Nails was pioneered in 1990, by Drs. Paley and Herzenberg while they practiced at the American Maryland Centre for Limb Lengthening & Reconstruction (MCLLR).
The procedure begins with the insertion of a metal rod into the central cavity (intramedullary) of the tibia in the lower legs and then the external fixator device is attached to the bone.
As the limb is lengthened, one end of the bone slides over the rod and new bone is grown around it. When the bone is fully lengthened, the external device is removed and the rod is surgically attached to each bone segment.
During bone strengthening, the rod provides support and the external device is removed, unlike the basic Ilizarov method.
After the consolidation phase, the metal rod is removed and the bones will heal shortly afterwards. This combination approach decreases the duration of the consolidation phase by two to three months.
Monorail fixators use a similar principle to the Ilizarov technique, but there is a small, lightweight bar that runs along the outside of the bone instead of a large external frame. The bar manages the process of distraction, and slowly pulls the two separated parts of the bone apart, but with less trauma than the Ilizarov method as there are less puncture wounds and parts involved.
Diagram showing monolateral external fixator:The most common Internal Methods are:
ALBIZZIA AND ITS SUCCESSORS, THE GNAIL AND BETZBONE
This approach was originally developed by Dr Jean-Marc Guichet at the University Centre (CHU) of Dijon, France in 1986. It is similar to Lengthening over Nails, but the internal device is spring-loaded and is extended by a movement of the patient's legs, rather than some external influence. This means that there is no need for external devices, minimizing wounds, trauma and pain. Being wholly internal has many benefits for lengthening, but is the most expensive form of Leg Lengthening
While the original Albizzia nail is no longer in production, Dr. Guichet in France has developed a successor nail named the Gnail, and Dr. Betz in Germany has developed a successor nail named the Betzbone. Both nails are reported to be stronger and more reliable than the original Albizzia nail.
Diagram showing an internal telescoping rod (Nail) during a femur lengthening:
This method is named after Professor Alexander Bliskunov, now deceased, who pioneered it in Ukraine when it was part of the Soviet Union, and it is still practiced in Kiev.
It is very similar to the Albizzia method, and involves the patient rotating a limb to extend the device and initiate distraction, but the patient rotates the whole leg rather than the foot or ankle.
You can find more information here: http://www.lengthening.ukrpack.net/faq.htm
This is an electronic system used for Leg Lengthening.
This is an electronic device used for Leg Lengthening. It has an nail device like in other internal methods, but the distraction is controlled by an external device that uses magnets to control the telescopic movement of the nail.
The nail is attached to each end of the cut bone and, as the nail extends, it stretches the bone.
This procedure was invented by Prof. Augustin Betz of Germany and is the first method to use an automated system: http://www.fitbone.de/fitbone_en/
INTRAMEDULLARY SKELETAL KINETIC DISTRACTOR (ISKD)
The ISKD was invented by Dr. J. Dean Cole, an orthopaedic surgeon and President of Orthodyne Inc. Dr. Cole is Medical Director of the Florida Hospital, Orthopaedic Institute, Fracture Care Centre.
This is similar to, and may have inspired, the Albizzia approach. Here, the internal nail, or Intramedullary Skeletal Kinetic Distractor (ISKD) device uses a kinetic clutch mechanism to allow distraction.
One segment of a rod is screwed onto another and the whole rod is inserted into the patient's bone. When the patient rotates his or her leg, one segment rotates over the upper other, and the rod lengthens, stretching the bone. The mechanism is clutched to ensure that it only rotates in one direction, and an external monitor tracks the rate of distraction.
There have been a number of recent recalls of ISKD devices and the reliability of the unit has been drawn into question. It is currently NOT recommended for prospective patients to lengthen with the ISKD.