Ilizarov Technique Revisited

Since G. A. Ilizarov described a revolutionary technique in 1950 while working in a remote town of Siberia, lot of work has been done to understand the intricacies of this technique popularly known as the ?Russian Technique? or just the Ilizarov technique.

It is interesting to note that though Ilizarov described the law of tension stress in 1950, the rest of the world was totally unaware till the Italians accidentally discovered the technique in 1980?s. Since then it has been widely practiced all over the world and lot of further research has been done since then. The initial euphoria has now gone and we understand and use the technique in a better way now.

This article is written to clear few of the misconceptions, which many doctors still have in their mind. I have to state here that this surgery has gone out of favour mainly due to its "Abuse" rather than proper "use".

For a quick recap let's see what an Ilizarov technique is,

The Ilizarov Technique

Ilizarov described a technique based on what he called the principle of tension stress. He found out that if the cut ends of the bone are distracted in a rhythmic fashion using a ring fixator, then there is new bone formation in the gap created and there is also simultaneous growth of the other tissues like muscles and nerves. The ideal rate of distraction was found to be 0.25mm every six hours. DeBastiani later on described a technique known as ?Callotasis? i.e. stretching of the callus based on the Ilizarov principle.

Applications of Ilizarov technique in today?s practice.

1. Limb lengthening
2. Deformity Correction
3. Infected Non-unions
4. Treatment of Joint Contractures e.g. post burns
5. Treatment of some acute fractures
6. Arthrodesis
7. Treatment of Arthritis

Limb Lengthening Procedure

Limb lengthening is normally advised when the discrepancy between the two limbs is 5 or more centimeters. Limb lengthening is also done for cosmetic reasons in dwarfism e.g. Achondroplasia, where both the limbs are lengthened.

What are the common causes for limb length discrepancy?
1. Congenital deformity or absence of a bone e.g. Fibular hemimelia
2. Post-traumatic e.g. mal or non union of a fracture
3. Epiphyseal Injuries either due to infection ( septic arthritis of the hip) or trauma
4. Neurological e.g. Polio or cerebral palsy
5. Metabolic Bone Diseases
6. Vascular Causes e.g. Arteriovenous fistula or haemangiomas
7. Rare Causes e.g. congenital hemiatrophy

Bones commonly lengthened

Any bone can be lengthened, however limb length discrepancy in lower limbs is a major problem it is the tibia and femur, which are commonly lengthened.

Age at which lengthening can be done

Since active physiotherapy plays a very important role in the treatment a child undergoing limb lengthening should be atleast five years old. It has also been observed that the bone formation is better during the growing phase and it slows down considerably as the age increases.


Site of lengthening

The metaphysis of the bone has shown to be the ideal site for lengthening.

How much can one lengthen the bone?

Theoretically any amount but the research has shown that the complications are minimum if one lengthens the bone upto 20 to 25% of its original length. Achondroplasic dwarfs (the tiny jokers seen in circuses) are an exception to this rule. This particular group tolerates lengthening to a much larger extent without complications.


How long does it takes to lengthen say 5 centimetres?

The lengthening procedure id divided into three phases

Phase I:

This involves application of the Ilizarov fixator and creating a break in the bone. There is a delay between this phase and the next phase i.e. Distraction phase. This delay depends on the age of the patient. In young children this delay is 7 to 10 days whereas in adults it is 14 days.

Phase II:

The actual distraction of the cut bone ends starts. Though Ilizarov described 0,25mm every six hours as ideal rhythm, it was subsequently found out that the rate and rhythm needs to be tailored to each patient. Again the adults do well with 0.25mm twice a day and children can distract at 0.25 four times a day. A too rapid distraction causes less bone formation and a too slow a distraction can prematurely fuse the cut bone ends. The distraction continues till the desired length is achieved.


Phase III:

Once the distraction is completed the phase of consolidation begins. The fixator is kept in place till the new bone is strong enough to take the weight of the body on its own. Once this is achieved the fixator is removed and a cast ids given.

Example:

A 7year old child needs 5cm lengthening.

Delay before distraction = 7days
1mm per day for 50 days=5cms
Consolidation phase 2 x phase II= 100 days

Total= 7+50+100 = 157 days or roughly 5 months i.e. 1 month per centimeter


An adult of 24 needing 5cms

Delay = 14 days
0.5mm per day = 100 days
Consolidation = 200 days

Total = 14+100+200 = 314 days

This amounts to almost one year?

True. But now a days this problem of using the fixator for a period of as long as one year has been tackled by what is known as lengthening over a nail. In this technique ( See figure) the lengthening proceeds as usual but with an intramedullary interlocking nail in situ. As soon as the desired length is achieved the fixator is removed and at the same time the nail is locked distally. The nail serves as an internal splint till the bone consolidates and the patient is free to walk without the hassles of a fixator. Therefore the adult in our example will spend only 114 days in the fixator as compared to the child!

Why not use the same technique (lengthening over a nail) in a child?

Children have a growth plate called as an epiphysis which can get damages easily while inserting a nail and nailing is therefore contraindicated I a child.

Can a patient walk during the treatment?

All patients are encouraged to walk as this aids in bone consolidation.

What are the complications?

1. Pin tract infections

The wires and half pins act as foreign bodies and if they are not properly cleaned every day can lead to pus formation and subsequent loosening.

2. Joint Stiffness

The stretching of muscles leads to adjacent joint contractures. Knee stiffness is commonly associated with femoral lengthening. A good physiotherapy regimen and patient cooperation usually helps to resolve the stiffness.

3. Injuries to blood vessels and nerves during the insertion of wires

A known complication but fortunately a rare one.

4. Pain

Pain was a problem initially but with modern medicines and good physiotherapy it has been easily controlled.


Other uses of this technique

1. Deformity Correction

Deformities either acquired (due to trauma) or congenital (since birth) can be successfully treated with Ilizarov technique. Many of these deformities are associated with limb shortening and simultaneous lengthening can be achieved which is real benefit. Multiplaner deformities can be easily tackled by an Ilizarov fixator.

2. Infected Non-unions

During the limb-lengthening phase it has been observed that the blood flow to the limb increases by 400%. In infection the principles of treatment include a through debridement ( removal of all dead tissues), stability at fracture site and insuring a good blood supply. Ilizarov method not only fulfills al these criteria but also can increase the length of the limb if it is short after taking away all the dead tissues. Ilizarov technique has revolutionized the treatment of infected nonunions.
This increase in blood supply has been used in the treatment of Burger?s disease ( Thromboangitis obliterans)

3. Treatment of Joint Contractures

In conditions like severe burns or polio patient may have a contracture across a joint, which hampers the function of that joint. One stage correction is usually not possible due to contracture of the neurovascular bundle. In such situations the Ilizarov method of gradual distraction is very useful.

4. Treatment of certain acute fractures.

Fractures at peculiar parts of the bone like a pylon fracture of the tibia are difficult to treat with standard implants. Ilizarov fixator can be used in such positions.

5. Arthrodesis.

Arthrodesis or fusion of a joint is a common surgery and some of the joints like the ankle joint very difficult to fuse. Ilizarov method has made arhtrodesis very easy. Knee arthrodesis after a failed total knee replacement surgery where the failure is due to infection is a difficult proposition and one of the ideal indications for an Ilizarov surgery.

6. Treatment of arthritis

Recent evidence shows that distraction of an arthritic joint can lead to pain relief for a significant period of time. Italians have distracted hip joints successfully for osteoarthritis of hip.

7. In peripheral Vascular Disease to Increase Vascularity

Though mentioned last this use has been highlighted because very few doctors are aware of it. Peripheral vascular disease likes the classical "Smoker's arteritis involves all arteries of the limb and commonly results in the tragic amputation. Ilizarov's basic research had shown that the blood supply to a limb being lengthened increases by 400%. This fact is utilized in the treatment of infected non-unions where the blood supply plays a paramount role in the management of infection. This same principle of increased vascularity is used in treating the arteritis cases. The affected limb, usually the lower limb is operated upon at the tibial level and a linear corticotomy id done of the tibia. Once the vascularity is increased the fixator is taken off. A preoperative and a postoperative angiography obviously are a must. However there is no data available about this procedure being used in diabetic angiopathy.

What is the hospital Stay?

Usually 5 to 7 days. Epidural anes6thesia is used for most of the lower limb surgeries and an epidural catheter is kept in place for three days post-op to control pain. This effectively creates a pain free surgery.

It must be a traumatic experience to go through such a long treatment?

Yes. However before the patient is taken up for surgery the entire family is given maximum possible information about the procedure and an effort is made to clear all the doubts. In certain case a psychologist?s help is sought. Patients of infected nonunions for example usually have already undergone multiple surgeries which makes them apprehensive and they can be depressed too. Information reduces the anxiety in such patients and usually talking to another patient helps. I maintain an address book of all patients and this really helps.

The most commonly asked question ? Can we use this technique to gain limb length solely for cosmetic purposes (or can my five foot daughter be made five six?)

Limb lengthening looks like a bed of roses to many short people on the streets!! None of the first timers actually know the procedure details and their enthusiasm fades once the whole process is outlined. Obviously doing such a major surgery without letting the patient know the complications as well as the time taken can only result in a disaster. I would advise to lay all the cards open and let the patient make a choice whether he or she wants a cosmetic limb lengthening.

Conclusion
Ilizarov technique is a specialized surgical technique, which has a very steep learning curve. The results of this technique can be disastrous in an untrained surgeon's hands and hence someone who has inadequate experience should not attempt this surgery. Constant research has solved many problems in this technique and further research is going on to find newer applications of this revolutionary technique.

Dr. Shreedhar Archik is a consultant Orthopedic Surgeon attached to Lilavati Hospital. He has done basic and clinical research in the field of limb lengthening at the Oxford University and was awarded a M.Sc. degree by the Oxford University for the same work. Dr. Archik specializes in the management of trauma and trauma related complications.