The Hindu
20 May 2010
New Delhi, India

A replica of knee joint. For patients saddled with unsuccessful artificial joint implants, a new technology used in surgery for the first time in AIIMS recently offers a lot of hope.

For patients saddled with unsuccessful artificial joint implants, a new technology used in surgery for the first time in AIIMS recently offers a lot of hope.

Billed by experts as the next best thing for the bone, trabecular metal technology, introduced in India recently, is an effective alternative for use in surgeries to fix bone defects.

A revision or redo joint replacement surgery is needed in patients whose once implanted artificial joint fails or becomes weak following years of use.

The technology, used in a surgery for the first time in India recently at AIIMS, is a boon in a country where cadaver donors are limited.

Made of porous tantalum, the material is porous, elastic, strong and ductile just like a normal bone, and simulates bone not only in appearance but also in behaviour.

Designed particularly to address bone defects encountered during the revision joint replacement, trabecular metal is an artificial material which looks like the metal replica of trabecular or cancellous bone

Its use manifests itself best in cases when a patient who has an artificial joint implanted needs a revision surgery after the artificial joint becomes weak to sustain itself.

The use of‘structural allografts’ or segments of bone from a person who donated at the time of his death, is plagued by the problem of too less donors against too many patients.

But, with availability of the metal, a person needing a redo joint replacement does not need to wait for a donor.

A well done joint replacement lasts normally for 15 to 20 years but it may last for a shorter period of time in a young person who overuses the joint, says Dr Rajesh Malhotra, senior professor of Orthopaedics at AIIMS, who conducted the surgery using the new technology at the institute.

However, the cost at Rs. 1,40,000 for every component or segment is quite high at the moment. Add to it the over one lakh cost for a redo process burns a hole in the pocket.

“We believe as the use grows and turnover increases, the price starts coming down, this is true for every product,”he says.

“A lot of bone is lost when we dismember the artificial joint before recreating it. We take out the old implant, try to preserve as much bone as possible, then assess how much damage the bone has suffered,”Malhotra told PTI.

In the demolition phase, a lot of bone is destroyed and this is where the trabecular technology comes in handy when doctors are trying to make up for the lost bone, he says.

“We take out a dead person’s bones and replace them in another person, but the problem is you have to have a donor, and they are very few in India,”Malhotra says.