'Double-bundle' used to fix knees

The surgeon who operated on the damaged left knee of Tiger Woods is known for advancing a novel procedure that may help restore the top-ranked golfer's swing.

Thomas Rosenberg practices at the Rosenberg Cooley Metcalf clinic in Park City, Utah, a Rocky Mountain ski resort center. While the doctor isn't saying what technique he used on Woods, he is an early developer of the "double-bundle" reconstruction of the anterior cruciate ligament, or ACL.

Most surgeons repair a damaged ACL, which Woods tore, with a single strand of tendon tissue, usually taken from the patient's knee or from a cadaver. Rosenberg pioneered replacing both of the two parts of the ACL.

Some specialists believe this may preserve the finely tuned "screw" action of the knee as it hinges, said John Richmond, chairman of orthopedics at New England Baptist Hospital in Boston.

"The anterior cruciate ligament guides the knee joint," said Richmond, who uses both methods. "The perceived advantage of double-bundle surgery is that it restores a more normal motion."

Rosenberg, 61, is known as an intense, quiet, private man who is a good athlete and avid golfer. He is team physician to the U.S. ski, skating, and snowboarding teams. He declined to comment for this article.

Woods, 32, is expected to recover from his ACL reconstruction, which took place six days ago, and the surgery won't have any "long-term effects on his career," Rosenberg said in a statement. It was the golfer's fourth knee surgery.

Rosenberg cleaned cartilage from the same joint two months before Woods won the U.S. Open. He played on the hurt knee over five days because of a 19-hole playoff.

The knee joint is similar to a door hinge in lacking side-to-side flexibility like that of the ball-shaped shoulder joint. Woods' 125-mile-an-hour swing involves sharp, excessive knee rotation that can damage ligaments, said Arnold Scheller, an orthopedist who retired as team physician of the Boston Celtics last year.

"When you follow through, you rotate about 70 to 80 degrees across the knee," said Scheller. "That's a lot of rotational torque, and he's got a very powerful swing."

Rosenberg first described the double-bundle technique in 1994, said Richmond, who says he has heard his colleague lecture on the approach frequently.

In a healthy knee, the two parts of the ACL, the anteromedial and posterolateral bundles, tighten and loosen independently as the joint flexes, giving the joint what surgeons call a "screw-home" motion, said Ralph Gambardella, president of the Kerlan-Jobe Orthopaedic Clinic in Inglewood, Calif.

While single-bundle reconstruction gives good results, the double-bundle is closer to the natural anatomy, he said.

Gambardella, Richmond and other orthopedists emphasized that scientific studies haven't shown the two-strand approach is superior to the more common single-bundle procedure. Surgeons said the double-bundle technique is more difficult, requires more drilling into bone, and is more expensive.

Rosenberg also often uses a piece of the patient's hamstring rather than knee tissue, called the patellar tendon, to reconstruct the damaged ligament, said Craig Morgan, president of the Morgan-Kalman Clinic in Wilmington. That may help patients avoid knee pain that sometimes occurs in the area of the missing tissue.

"Tom was one of the first to get away from using the patellar tendon and use hamstring autografts," said Morgan, who just performed shoulder surgery on Boston Red Sox pitcher Curt Schilling. "He's a very creative thinker."