Key Points:

BEIJING - China has banned the controversial practice of leg-lengthening, a cosmetic surgery procedure popular among young professionals who believe height will help them climb the career ladder, after a rash of botched operations has left patients disfigured.

Leg extension surgery is a procedure that looks like something out of the Middle Ages.

A doctor breaks the patient's legs and inserts steel pins into the bones, just below the knees.

The pins are then rigged up to a metal frame that looks like a cage and every day for months the patient tightens the knobs a small amount despite excruciating pain.

By constantly forcing the ends of the broken bones apart before they can heal, more new bone comes to fill in the gaps.

"Leg-stretching surgery for the image conscious has been banned by China's Health Ministry after a spate of botched operations," the Xinhua news agency reported.

The operation costs around 100,000 yuan and it is often six months before the patient can walk without using a walking frame.

Many can never run again after the operation.

From now on, leg extensions may be carried out by hospitals that conduct at least 400 orthopaedic operations a year and offer post-surgery care and rehabilitation, and only on strictly medical grounds, the ministry said in a circular.

Chinese people's increased sensitivity about their appearance has seen a rash of cosmetic surgery clinics springing up around the country, offering a huge array of different kinds of surgery, including leg extensions.

Many of the clinics are run by doctors who abandon poorly paid work from the state-run medical system to cash in on the appetite for nips, tucks and leg extensions.

Chinese people are generally not tall by European standards -- the average Chinese woman is about 5 feet 2 inches, while the average male is about 5 feet 6 inches.

However, improved living standards mean Chinese people are getting taller -- about two cm taller than a decade ago - and one of the tallest basketball players in the world is China's NBA star, Yao Ming, who stands 7 feet 5 inches, tall.

Being tall has really only become an issue in China since the economic boom -- the architect of the country's opening up, Deng Xiaoping, stood less than five feet tall.

But nowadays many Chinese people feel discriminated against in their jobs if they are not tall or good-looking enough.

Men wear step heels, or inches-giving in-soles and TV ads show the footwear with its inches-giving insoles.

And they are indeed discriminated against in some cases -- some job ads have height requirements, especially in the service industry.

The technique of leg-lengthening was conceived by Italians in 1905, but the Russians can take credit for developing the concept.

Much of the breakthrough work was done by Doctor Gavril Ilizarov, who used bicycle spokes to heal fractured bones broken by gunshots.

He later adapted this technique to lengthening limbs.

It is now used all over the world but rarely allowed for cosmetic reasons in most countries.

Each year there are tens of thousands of stories of botched plastic surgery in China and many Chinese medical experts have been vociferous in opposing the practice, as they feel it is too risky.

According to Xinhua, the messed-up leg-lengthening operations carried out by unauthorised beauty clinics left patients both physically and psychologically scarred.

Ten people were reportedly disfigured after they underwent the operation last year at a Beijing hospital, lured by the promise of "height surgery without pain".

From now on, hospitals must tell patients about the risks involved, while only qualified personnel will be allowed to carry out the procedure.