Minimal stressing of knee may mean faster recovery

New England Patriots quarterback Tom Brady will probably be out of action at least six to nine months after suffering a season-ending knee injury Sunday, according to orthopedic surgeons, but the good news is that quarterbacks typically return to pre-injury form more quickly than other athletes.

The Patriots announced yesterday that Brady will miss the rest of the season because of the injury to his left knee. Coach Bill Belichick declined to release any further information about the injury, but it is believed to be a torn anterior cruciate ligament, or ACL, because of the angle of the tackle and the amount of time the team said he would miss.

The ACL is a fibrous band of tissue that runs from the thigh bone to the shin bone and provides stability for the knee during jumping, cutting, and pivoting maneuvers. It is one of four major ligaments in the knee, and an ACL tear is one of the most common knee injuries suffered by athletes. It's possible Brady also suffered other damage to his knee, which could lengthen his recovery.

Orthopedic surgeons who routinely work with athletes say quarterbacks generally place less strain on their knees than athletes whose positions require more explosive, side-to-side movement.

"Quarterbacks, in my experience, return more quickly then running backs and wide receivers, the guys who have to do the quick cutting and planting maneuvers," said Dr.Paul Weitzel, an orthopedic surgeon at the Boston Sports & Shoulder Center, which is affiliated with New England Baptist Hospital.

Weitzel, who works with the Boston Celtics, reconstructed the ACL in Celtics guard Tony Allen's left knee in January 2007. Allen missed the rest of the 2006-2007 season and struggled to come back last season.

But Weitzel and other sports specialists said basketball players tend to beat up their knees more than football players and require longer rehabilitation times because of the daily pounding on the court and their quick lateral movements.

Weitzel, who has viewed the video of the tackle that ended Brady's season and is not involved in his care, said the injury also probably includes damage to his medial collateral ligament, or MCL, which also connects the thigh bone to the shin bone.

"Fifty percent of ACL tears have a secondary injury at the same time," Weitzel said.

Dr. Frederick Azar, an orthopedic surgeon at the Campbell Clinic in Memphis, said that the MCL tends to be the first ligament damaged, either strained or torn, when an athlete's knee sustains a tackle or sudden blow.

He said such injuries typically also include some damage to the rubbery cartilage that cushions the bones inside the knee, known as meniscus. Recovery can be more difficult and take longer if cartilage is torn, he said.

"Sometimes you can repair [the meniscus]; if you can't, you tear out the torn part and leave the rest," said Azar, who is the team physician for the NBA team the Memphis Grizzlies, and is also on the board of directors of the American Academy of Orthopedic Surgeons.

Brady's injury conjures images of the knee damage suffered by another NFL quarterback, Carson Palmer of the Cincinnati Bengals. That story had a happy ending.

Palmer tore his ACL and MCL on Jan. 8, 2006, during a playoff game. He underwent surgery two days later and was back in uniform to start the season opener exactly nine months later.

"He played very sparingly in the preseason leading up to the [opening] game," said Bengals team spokesman Jack Brennan.

"But he has been fully healthy since the rehab and the recovery He played every game of the 2006 and 2007 season."

Philadelphia Eagles quarterback Donovan McNabb tore his ACL in November 2006 and was able to return to action in a preseason game in August 2007.

When Brady will undergo surgery is not clear, but some specialists prefer to wait several days or perhaps a week to perform ACL surgery, to allow swelling from the injury to subside.

In some cases, professional athletes perform exercises, known as prehabilitation, even before surgery.

"Studies have suggested that patients that do prehabilitation do better because they don't lose as much strength and range of motion and you can control the swelling," said Dr. Julio Martinez-Silvestrini, a rehabilitation specialist known as a physiatrist who works at Baystate Medical Center in Springfield.

Martinez-Silvestrini is the team doctor for the New England Mutiny, the region's professional women's soccer team.

"Athletes tend to recover faster from surgery if they do prehabilitation, but the end result after a year will be exactly the same" if you don't have prehabilitation, he said.

"But if you have an athlete who wants to play immediately, prehabilitation may get them back closer to six months rather than nine."

Kay Lazar can be reached at klazar@globe.com.