Baby twins who were born joined at the spine have been successfully separated by doctors in Memphis, Tenn, MyFoxMemphis.com reported.

The 13-hour procedure was discussed Wednesday at a news conference by surgeons at Le Bonheur Children's Hospital.

Joshua and Jacob Spates of Memphis, who were connected at the pelvis and lower spine, were separated on Aug. 29 in the most complex operation in the prestigious hospital's 59-year history.

Joshua and Jacob were considered pygopagus twins, which means they were joined at the pelvis and lower spine. They shared a rectum, muscle and nerves, but had separate hearts, heads and limbs. 

Doctors discovered the twins were conjoined at 25 weeks gestation, and soon after they were born, doctors performed a colostomy and inserted a gastrostomy bag. 

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The boys will remain at Le Bonheur to receive follow-up care. 

Around 70 percent of conjoined twins are female.

Click here to read more from MyFoxMemphis.