On Monday, Dr. Dean Richardson replaced a pair of bent screws and implanted three new ones in the Kentucky Derby winner's right hind leg. Richardson also changed the colt's cast.

Two weeks after winning the Derby on May 6, Barbaro broke down in the Preakness Stakes, shattering his leg and ending his racing career.

The initial surgery May 21 for life-threatening injuries had Richardson placing 27 screws and a compression plate in the leg. Barbaro has been in intensive care at the George D. Widener Hospital for Large Animals at the University of Pennsylvania's New Bolton Center in Kennett Square, Pa.

Even though Barbaro isn't out of danger, X-rays show Barbaro's joints are fusing and the breaks healing.

"This is about the time we expect to see good evidence on radiographs of a degree of healing, and the X-rays that were taken (Monday), they look very, very good," Richardson told the Daily Racing Form. "As far as the major fracture, basically, it could not look better.

"He's really progressing well as far as the fracture goes."

Barbaro won his first six starts, including a 6 1/2 -length victory in the Kentucky Derby with jockey Edgar Prado for trainer Michael Matz. Barbaro entered the Preakness Stakes as the heavy favorite, but broke his leg in three places around the ankle shortly after the start.

Should Barbaro continue to improve, the injury will not prevent him from breeding and his stud value is expected to be high.