Times of India
10 March 2011
Lucknow, India

Surgical Technique At MU To Help In Treatment of Bone Deficiency In Skull
Verma Prasad, 28–year–old, sustained high voltage electric shock while working in his field when he accidentally came in contact with a wire hanging loosely. He was immediately taken to a district hospital for treatment.

It took four weeks for him to recover but the electric shock damaged his a bone on skull. The bone was reduced to a thin parchment with no hair or skin over, leaving brain vulnerable. Even a minor injury would have resulted in immediate death. He was referred to the Chhatrapati Shahuji Maharaj Medical University (CSMMU) where surgeons in the department of plastic and reconstructive surgery (PRS) repaired his skull through ‘distraction technique’.

Traditionally used to fix bone loss in limbs, the technique was used for the first time at CSMMU to treat bone loss in the head. Prasad is now healing.

Distraction is a technique of regenerating new bone in the human body. The technique was discovered and developed by a Russian doctor Dr Gavril A Ilizarov in 1960s. Few places in human body can regenerate lost tissue. This capability is more seen in animals where lost tissues like the tail of lizard etc regenerates but in humans once a tissue is lost, it is lost forever. In such cases the plastic and reconstructive surgeons have to think of methods to either put an artificial implant or the patient has to bear the loss throughout his life.

But distraction technique helps in regeneration of natural bone in the body at all ages. It can be used in areas of the body where the bone has been lost either by accident, trauma, disease, after surgery or even if the bone is absent or less developed since birth. The technique is being used to fix limb bones since long. Gradually, it also became a major treatment arm for treating bone defects in the facial region but now it has been innovated by Prof Rajiv Agarwal, PRS department, CSMMU, to be used for treatment of bone deficiency in the head region of the skull. When used in skull, the distraction technique is known as "calvarial distraction".

"It has given satisfactory results and has been recently accepted for publication in a reputed international journal of craniofacial surgery," said Prof Agarwal.

A defect in the face bone has can cause morbidity, asymmetry of the face but a defect in the skull bone can have grave consequences.

It exposes the underlying brain to injury and hence is extremely vital to correct at the earliest opportunity. Doctors have been doing craniofacial surgeries to treat deformities of face, jaw and skull since long but now the calvarial distraction technique has opened a new dimension to regenerate lost skull bones.Prof Agarwal has improvised tools used for distraction in other parts to use it for skull bone. He has also applied for the patent of the tools.

Calvarial distraction has come as a boon for people suffering from skull bone defects, he said. These defects could be due to variety of reasons from accidents to assaults with blunt objects, gunshot injuries, fracture of the skull bones leading to loss of a fragment and after surgery for reshaping the head for congenital deformity among others.

"A full thickness defect of skull bone is a tricky situation where the underlying brain if not covered by scalp is very prone to injury and any direct injury over brain can result in instant death. It is urgent to treat these cases," said Prof Agarwal.

Several cases in the last 2 years have been treated by this technique.
All the patients were suffering from loss of head bone. "All the patients treated so far have recovered are leading a normal life," said Dr Ateesh Borole, a member of Dr Agarwal’s team.

Distraction Technique
The technique of performing calvarial distraction needs close cooperation with neurosurgeon. A matching disc of skull bone needs to be carved out on the adjoining skull near the defect. This skull disc is then moved across the defect and as this moves, new bone formation takes place behind its path METHOD 1 Two cuts are made in the head bone of the skull on the either side of the affected areas.

The size of the cuts are identical to that of the affected area with bone loss 2 Distraction devices are fixed on two bones in a way that they push them towards each other to fill in the bone loss area. As the two bones move towards the affected portion, the bone tissues are naturally generated in area left behind them 3 So, as the two bones gradually cover the affected portion, the area left behind them gets covered with the regenerated bone material 4 Movement of the two bones towards each other is approximately at the rate of 1 mm per day.

Time taken in the treatment depends on the size of the bone loss area
OLD PROCEDURES | Commonest method is to take bone from any other site or part of body like adjoining skull, ribs, iliac crest which is then used to bridge the defect. This however is an age old traditional treatment and entails problems resulting from taking the bone from the body. Using the ribs can lead to deformity of the rib cage, chest complications and other problems. The second method to treat skull bone loss is by using artificial materials like implants and artificial bone substitutes.

There can be many problems in use of these consisting of high infection rate, prohibitive cost of implant, and implant rejection. Hence treatment of skull bone loss has been a problem area for plastic surgeons

COST | The cost of the treatment is around Rs 30,000 at CSMMU which includes hospitalisation, surgery and drugs. Distraction devices are the major component of the cost. These devices are custom made for the head bone in the skull. They cost around Rs 20–25,000 Advantages
Natural bone is regenerated.
No need of taking bone from any other part of the body.
Avoids all the potential complications associated with taking bone from any other part of body No need of costly implants.

Constraints
Requires high degree of training, expertise in craniofacial surgery.
Requires close cooperation with neurosurgeon.
Requires knowledge and experience with modulating the regenerate in distraction