07/04/2006 12:00AM

Barbaro 'progressing well'

Sabina Louise Pierce/Univ. of Pennsylvania
At the New Bolton equine hospital, Dr. Dean Richardson leads Barbaro past doors adorned with get-well cards.

Dr. Dean Richardson, who performed surgery Monday on Kentucky Derby winner Barbaro to replace a pair of bent screws and implant three new ones in the colt's injured right hind leg, said that the new repairs were the result of force and motion in the affected area and do not signal a problem in the healing process.

Barbaro's X-rays continue to show bone healing about six weeks after his breakdown in the Preakness Stakes, a positive sign.

"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 yesterday, they look very, very good," Richardson said Tuesday in a phone interview. "As far as the major fracture, basically, it could not look better. He's really progressing well as far as the fracture goes. All in all, it was a reasonably satisfactory day."

On May 21, one day after Barbaro shattered his lower right hind leg early in the Preakness, Richardson implanted 27 screws and a compression plate in the leg in an attempt to stabilize the fractures and allow the bone to heal. Since then, Barbaro, a 3-year-old Dynaformer colt, has been in intensive care at the University of Pennsylvania's New Bolton Center in Kennett Square, Pa., where Richardson is chief of surgery.

Richardson said Tuesday that for several days Barbaro had showed a slight elevation in body temperature, "up about a half a degree to a little bit more," and was walking differently on both hind limbs. Those changes prompted Richardson to examine the leg and change the cast.

"The reason we changed the screws is that he had two broken screws that crossed the pastern joint," he said.

Richardson said that the screws he replaced were in "the least important part of the fixation" and that veterinarians knew bent screws in that area would be fairly likely.

"That is an area that we knew was going to be vulnerable to have the implants break, because there's a lot of force and motion that's occurring at the pastern joint, because everything is locked down above it. The end of the plate is there, and it's tending to move, and he's been very, very active on his cast.

"This doesn't affect his fracture per se, but it does affect how quickly I would be able to get him out of the cast if his fracture continues to heal, because we need to have the pastern stable as well as the fracture. Because of that, we put these additional screws across the pastern joint to try and help stabilize it more."

Richardson said that as the bone heals around the implants and begins to bear more of the horse's weight, the screws will no longer be under load stress.

"All this surgery was done under fluoroscopic control, using little, small incisions, so it wasn't like you were opening the leg back up or anything," Richardson said. "These were done through one-centimeter incisions, so tiny incisions."

Fluoroscopy gives surgeons a live X-ray view of a patient.

Richardson also found that Barbaro has "a small infection" on the sole of his uninjured left hind hoof near the frog, a V-shaped cushiony growth that serves as something of a shock absorber. He said that the infection "appears not to be a big deal" and it is being treated topically.

Richardson cautioned that Barbaro is still not out of danger.

"He's six weeks out, and if you'd asked me six weeks ago would I be happy where we are right this moment, the answer would be yes," he said. "However, even though it's that long and we haven't had any major complications, the fact remains I know that there are bad things that could happen. Even though things are progressing well, he's certainly not healed yet. He's not out of the woods."