Thanks to advances in sports medicine, a torn ACL is not nearly the career killer it used to be.

That’s probably small solace to Warriors guard Klay Thompson as he begins the lengthy rehab period after tearing his ACL in his left knee Thursday night in the climactic Game 6 of the NBA Finals. He left in the third quarter after scoring a game-high 30 points in Golden State’s 114-110 loss to Toronto.

Many players have come back better than ever from the injury, which typically sidelines a player nine to 12 months. One of them was on the Oracle Arena court for Toronto. Kyle Lowry was still playing at Villanova when he tore his ACL in 2004. His injury hasn’t hampered his career a bit. Fifteen years later, he had 26 points, 10 assists and seven rebounds in Thursday’s title-clinching game. He is a five-time NBA All-Star.

Another is one of Thompson’s teammates. Long before he was a key part of three Warriors championships, Shaun Livingston blew out his left knee while playing for the Clippers in 2007. Landing awkwardly after a missed layup, he dislocated his left kneecap and tore his ACL along with his posterior cruciate ligament and lateral meniscus. At the hospital he was told his leg might have to be amputated. It took him many months after surgery just to walk again.

He spent the next five years with seven NBA teams before resurrecting his career with Brooklyn in 2013-14 and Golden State the past five seasons.

A member of the Warriors’ bench, guard Damion Lee, Stephen Curry’s brother-in-law, tore his right ACL while playing for Drexel. He later transferred to Louisville for his final college season. In 2016 he tore his left ACL while playing in the NBA Development League. Nevertheless, he made it to the NBA.

From 1970 to 2014, 97 players tore ACLs before or after their NBA debuts. There was even a group called the ACL Recovery Club that kept the list. Stats compiled by Hoops Rumors showed that nine of the 97 suffered the injury twice.

About the ACL

The ACL is a thick, index finger-sized cord. It stabilizes the knee and is one of four main ligaments that connect the femur (thigh bone) to the tibia (shinbone). An ACL tear is usually caused by a quick change in direction, often a freak accident on a routine play rather than the result of years of stress.

Dr. James Gladstone, chief of sports medicine at the Mount Sinai Health System in New York, said the medical community’s understanding of the ACL “is much better over the last 10 years. That means we’re able to do much better repair. It’s really called a reconstruction because a repair is sewing two ends to each other, whereas a reconstruction is putting something new to replace what was there.”

Repairing a partially torn ACL is rare these days, he said. “Ninety-eight percent of the time it’s a reconstruction.” Usually, the player’s own tendon — possibly from a kneecap, a hamstring or a quadriceps — is used for the ACL graft.

Wear and tear doesn’t really have anything to do with ACL ruptures, he said. For an NBA player, the “safest” timeline for recovery is nine to 12 months, he said.

At age 29, Thompson “has as good a chance as an 18- to 20-year-old of getting back,” Gladstone said.

How other players fared

Among the many players who have come back from ACL tears:

Al Jefferson — With the Timberwolves in 2009, the center landed awkwardly on his right knee after blocking a dunk attempt. He said he heard the ACL pop as soon as he hit the floor. He was 24 years old, averaging 23.1 points per game and 11 rebounds at the time. He appeared sluggish and stiff for a while when he returned, and Minnesota traded him to Utah. But his numbers bounced back with the Jazz.

Baron Davis — During an NCAA Tournament game with UCLA in 1998, he tore his ACL while coming down from a dunk. He played the next college season, was drafted No. 3 overall by Charlotte and played 13 years in the NBA, including 3½ with the Warriors. He was dazzling in the 2007 playoffs as they took down top-seeded Dallas before being eliminated by Utah. Davis had a memorable dunk over 6-foot-9 Andrei Kirilenko of the Jazz.

He tore his ACL again, along with an MCL tear and a partial tear of the patellar tendon, while playing for the Knicks in the 2012 playoffs. His NBA career was essentially over.

David West — Another ex-Warrior (2016-18), West suffered his tear in 2011 with New Orleans when he was 30. Before the injury, he was averaging 18.9 points. He became a free agent after that season and spent the next four years with the Indiana Pacers, averaging 14 points per game. He played on the Warriors’ last two championship teams.

Ricky Rubio - One of the best guards to come out of Europe, the Spaniard was guarding Kobe Bryant for the Timberwolves in 2012 when he tore his ACL, ending his rookie season. He returned nine months later. After six years with Minnesota and two with Utah, he’s still going strong.

Derrick Rose — Rose’s experience provides a more sobering message. A variety of knee injuries plagued the former NBA Most Valuable Player (2011) with the Bulls, including a torn ACL in the 2012 playoffs. He missed the 2012-13 season. Early in the following season, he injured his meniscus in his other knee and missed the rest of that season, too.

Rose was still capable of great performances, but injuries of all sorts have continued to bother him with the Knicks, Cavs and Timberwolves over the past three years.

Tom FitzGerald is a San Francisco Chronicle staff writer. Email: tfitzgerald@sfchronicle.com Twitter: @tomgfitzgerald