Twins who were joined at the spine are successfully separated after a pioneering - and incredibly risky - 18-hour operation

                       
Nigerian twins Hassana (left) and Hussaina (right) Badaru were separated during an 18 hour operation in New Delhi. They are pictured after the operation with their parents, Badaru Mannir and Malama Badariyya Badaru

Conjoined twins who shared spinal cords have successfully been separated during a gruelling eighteen-hour operation.

The operation on one-year-old Nigerian sisters Hussaina and Hassana Badaru involved 40 doctors, and is only the fourth such separation to be carried out in the world.

The pair, who were born with a condition called pygopagus in Kano, Nigeria, were joined at the hip and had spinal cord fusion, while also sharing a lower gastrointestinal passage and genitalia.

Specialist surgeons at BLK Super Speciality Hospital in New Delhi, India, conducted the separation on August 12.

They carried out two procedures - one to divide the twins, and one reconstructive operation.

The procedures - which cost an estimated £64,000 and were paid for by a Nigerian philanthropist - were so risky that doctors were forced to conduct practice runs on dummies before attempting it for real.