(CNN) -- The surgeon who operated Wednesday on cyclist Lance Armstrong after he fractured his collarbone declared the procedure a success, but one that will require two to three months of healing.





Lance Armstrong's doctor says he used a plate and 12 inch-long screws to stabilize the fractured bone.





"Surgery was tough, but went well," said Dr. Douglas Elenz, an orthopedic surgeon in Austin, Texas, who performed the three-hour procedure two days after Armstrong fractured his collarbone into four pieces during a race in Spain.





The multiple breaks "made treatment more challenging, but we're confident that the treatment performed today is going to be successful," he said.





Elenz said he used a 4- to 5-inch plate that he attached with 12 inch-long screws to stabilize the fractured bone.





Armstrong, 37, was to be released later in the day.





On a scale of one to 10 rating the difficulty of the operation,  Elenz said he would pin it down at eight.





Elenz was noncommittal regarding when Armstrong can return to racing.  Watch more about the crash »





"We are just taking it day by day, week by week, month by month. Every fracture is unique. Each time I go to treat one, something is different."





During the next week, Armstrong "will need to take it easy" to ensure the wound does not become infected, the doctor said.





After his wound has healed, Armstrong will begin using an exercise bike to train his lower body, "but we won't let him do a whole lot with his upper extremities," Elenz said.





"After several weeks, we can take his training to the street, but we will need to take that day by day and week by week."





Over the longer term, Elenz will be looking for evidence that Armstrong is laying down new bone, that the plate is stable, that the athlete's arm is strong and that his motion is fluid, he said.





"His pain will give us insight on how well he is healing," the sports specialist said. "It will take eight to 12 weeks to heal completely. But we are going to have to push the envelope a bit to have him train before he is completely healed."





Armstrong was riding for Team Astana when he crashed about 10 miles (16 kilometers) from the end of the first stage of the five-day Vuelta Ciclista a Castilla y Leon race.  Watch how Armstrong 'tweets' about his crash »





He has never before broken a collarbone in his 17 years as a professional.





The crash took down several riders, but only Armstrong was hurt.





As they came within a few miles of the finish, Armstrong said, racers started picking up speed and jockeying for position.





"It happens quick when it happens," he said. "It could have been worse."





Armstrong announced last year that he was returning to competitive biking and would use the Spanish race as a warm-up for the Tour de France, which he won seven times before announcing his retirement in 2005.





He also had planned to race May 9-31 in the Giro d'Italia, one of Europe's most prestigious and grueling stage races.





This would have been the second comeback of his career. His first came in 1998, two years after he was diagnosed with advanced testicular cancer that had spread to his lungs and brain. Doctors gave him a less than 50 percent chance of survival.





CNN's Danielle Dellorto contributed to this story.
Where were the multiple breaks? Who will use an exercise bike after the wound heals? What part of the body did Armstrong break? What will Armstrong use to train his lower body? What does the doctor say? Is Armstrong's doctor certain when he can start racing again?
collarbone Lance Armstrong collarbone exercise bike he used a plate and 12 inch-long screws to stabilize the fractured bone. Elenz was noncommittal
question: Where were the multiple breaks?, answer: collarbone | question: Who will use an exercise bike after the wound heals?, answer: Lance Armstrong | question: What part of the body did Armstrong break?, answer: collarbone | question: What will Armstrong use to train his lower body?, answer: exercise bike | question: What does the doctor say?, answer: he used a plate and 12 inch-long screws to stabilize the fractured bone. | question: Is Armstrong's doctor certain when he can start racing again?, answer: Elenz was noncommittal