A 2-month-old baby boy born with three arms underwent a successful operation yesterday at Shanghai Children's Medical Centre to remove his extra limb.

Liu Junjie was born with two malformed left arms and a normal right one.

The operation, which lasted less than 2 hours, removed the arm stretching out under the armpit of the other left one.

Surgeon Chen Bochang, head of the orthopaedics department of the hospital, said that the baby's remaining left arm bent slightly after the removal of the one under it.

It is still too early to say whether the baby will ever be able use his left arm normally.

"We found the two left arms shared part of their joint capsules," Chen said. The joint capsule is the "hinge" structure of the bone joint.

"We've managed to divide the capsules, but how well the split joint can work in future is not certain yet.

"Also, the left elbow joint could easily be damaged by the operation."

The baby is expected to recover from the operation in one to two months, but rehabilitation could take a long time, according to Chen.

The doctor said the hospital would train the boy's parents on how they can help with the rehabilitation.

The baby is in an intensive care unit and is expected to be transferred to a normal ward in three to five days.

Chen said that the malformation was the third instance of its kind in the world that he is aware of. "I just heard this week that a hospital in Houston, the United States, has received two similar patients,"

The baby also has other malformations including the absence of a kidney and spinal problems.

"But they are not very serious," Chen said.

Doctor Chen appealed to the public to donate money for Junjie's future treatment and rehabilitation.

The operation and treatment has cost above 20,000 yuan (US$2,470) so far, but the hospital has not charged the parents, who are poor farmers from Anhui Province.

Editor: Yan