Like any human tissue, bones also have the property of regenerating themselves. At G.B. Mangioni Hospital, part of GVM Care & Research, Professor Maurizio Catagni, specialist in Orthopedics and Traumatology, performs about 200 interventions a year with the Ilizarov technique which allows bone regeneration and lengthening of the limbs. In his vast experience, he subjected patients with a minimum age of 11 months to 81 years to this technique.

The first Italian patient to test this new technique was Carlo Mauri, a mountaineer from Lecco. After breaking his tibia during a climb, in 1979, and after three surgeries, his limb was deformed and shorter than 4 cm, also suffering from clubfoot and infected pseudarthrosis. He thus decided to go to Siberia, where a certain doctor, Gavriil Abramovič Ilizarov was successfully experimenting with the method of bone regeneration, a revolutionary technique. After six months, he returned home completely healed, the limb had returned to its natural length and the pseudarthrosis had also disappeared.

What does the Ilizarov technique consist of?

Ilizarov exploited a characteristic of human tissues and also of bones: the regeneration.

It is a natural phenomenon that can be exploited to:

• lengthen a limb in case of discrepancy (one leg longer than the other), congenital or acquired;
• lengthening of the limbs (lower and upper) in cases of dwarfism (achondroplasia);
• correct congenital or post-traumatic deformities of the long bones;
• treat cases of pseudarthrosis, including infected ones, or delays in the consolidation of fractures that do not heal;
• treat congenital or post-traumatic foot deformity;
• reconstruct loss of substance of long bones even in the aftermath of resection resulting from neoplasms.

His technique involves the interruption of the bone segment, through a deliberately procured fracture and the distancing of the two parts. It is at this point that the bone reacts with histogenesis, ie the regenerative action of the tissue with the birth of new cells. The more the two parts are separated, the more tissue is formed, thus obtaining elongation.

The tool needed to achieve this is a circular fixator, a cylindrical cage that is placed around the leg. It consists of a series of circles spaced by small rods to which wires and screws are connected that are implanted in the bone at the time of surgery. These rods are extendable and allow the doctor to gradually increase the distance.

How far can the distance be increased?

Each operation and each patient must be studied individually – explains Professor Catagni, – the standard is 0.25 mm 3 times within 24 hours. For example, if we are faced with a problem of deformity of one leg (one longer than the other), the necessary length is extended to make up the difference. In patients suffering from dwarfism, the elongation of the tibiae is 14-16 cm, that of the femurs 10-12 cm, that of the humerus 10-12 cm. The whole body and its harmony must always be evaluated; excessive stretching can cause damage to the knees and ankles. Modern circular fixators, modified precisely in Lecco, follow the bone and its regeneration, avoiding incorrect growth.

What happens to the muscles, tendons, vessels and nerves during this process?

The lengthening, performed gradually, allows the soft tissues to regenerate and adapt to the new circumstance.

Generally, at what age is the first surgery recommended in case of achondroplasia?

As a rule, the first treatment is performed around the age of 10-11 and continues with well-defined steps. It begins with the lengthening of the legs, continues with that of the arms to balance the disproportion between the lower and upper limbs and finally with that of the femurs.

On the other hand, in the event of a limb length discrepancy, when should you undergo this type of surgery?

If it is a severe discrepancy, with a prognosis of 8-10 cm at the end of growth, the indication is to undergo surgery when the limb length discrepancy reaches 4-5 cm, so as to plan an early first procedure and one towards the end of growth. If the discrepancy, calculated with special tables, will not be greater than 3-4 cm, the indication for treatment will be towards the end of growth, when the vivacity of the bone is still good.

Is it a painful surgery?

Yes, it is painful, but less than before, because the fixators have been modified and perfected. Today, these devices allow great stability, that is, they are connected to the bone and keep it under control during lengthening in order to prevent it from growing in the wrong direction.

Does the treatment of pseudarthrosis have limits?

Bone reconstruction can be performed at any age, respecting the biology of each patient. Certainly some situations can be adverse, such as diabetes, smoking or chronic vascular disease, but, basically, the result is always achieved but with more prolonged times.

Is it possible to apply the elongation for aesthetic reasons?

Sure, for selected cases. The first surgery of this kind was done in the early 1980s and by now we have done at least 200. The segment that is stretched is the leg for an entity of 6-8 cm with a treatment time of 10-12 months with a fixator. The aesthetic lengthening of the femur can be done with an external fixator or, better, with a motorized intramedullary nail.

What type of fixator is used?

The traditional circular one (today with carbon rings and very stable fixation) in simple elongations, while in the correction of deformities circular fixators are always used but with a “hexapodalic” ring connection system that can be planned with a computerized digital program.

What if the patient has an allergy to steel?

In cases where subjects have an intolerance to steel, we use titanium fixers.