DUESSELDORF, Germany — The medical treatment for Lindsey Berg’s arthritic left knee has not been approved by the Food and Drug Administration, and neither her professional volleyball team in Italy nor the U.S. Olympic team would help with the cost. But for Berg, a gold medal hopeful, the chance to dull the chronic pain was worth the money and the risk.

So between the end of her professional season and the start of Olympic practices in California, Berg stopped at the office of Dr. Peter Wehling on the bank of the Rhine River.

“I’ve been struggling with knee pain for the last four years and just continuing to play on it,” said Berg, 31, who had tried surgery and cortisone injections to little avail.

After examining her, Wehling and his team drew syringes of her blood. First they incubated it. Then they spun it in a centrifuge. The blood cells produce proteins that reduce inflammation and stimulate cellular growth; sometimes additional anti-inflammatory proteins are added to the solution. Finally, Wehling injected the orange serum into her knee.

The price came to 6,000 euros, or about $7,400, out of her own pocket, but with the Olympics in London coming up, any treatment that might make her knee better was worth it.

“It’s your body and your money because they’re not paying for it,” she said, with cheerful resignation, on the fourth day of her treatment.

Wehling’s practice has become almost a pilgrimage site for athletes trying to prolong careers that have tested the limits of their bodies. It has also been the subject of no small amount of speculation after word leaked last year that the Los Angeles Lakers star Kobe Bryant had flown to Duesseldorf for the treatments. Alex Rodriguez of the New York Yankees traveled there as well. After the NBA season ended, Lakers center Andrew Bynum, Bryant’s teammate, said he, too, would try it.

Commentators wanted to know if there was something fishy that required Bryant to go abroad for medical treatment. As his scoring average increased and the aging star seemed rejuvenated, the interest in the trips to Germany and the unusual treatment grew.

To answer the most common questions: Wehling’s practice is not at the end of a dark alley but in a modern building south of the city’s old town; it is brightly rather than dimly lighted, with orange floors and a water cooler in the waiting room; and Wehling seems more like a true believer in his Regenokine therapy than a snake-oil salesman. He said he was careful not to use any substances banned by athletic governing bodies.

Biologic medicine is a rapidly growing field. Wehling’s Regenokine treatment might sound similar to another blood-spinning treatment, known as platelet-rich plasma, or PRP, that has gained popularity in the United States in recent years. In that procedure, the goal is to produce a high concentration of platelet cells, which are believed to speed the healing process. Wehling said his treatment differed from PRP because he heats the blood before it is spun to increase the concentration of anti-inflammatory proteins, rather than the platelets, in his cell-free solution.

The idea is not just to focus on mechanical problems in the joints or lower back but to treat inflammation as a cause of tissue damage as well as a symptom.

“The potential of biology to treat orthopedic problems is high because it has only been developed a little,” Wehling said in an interview.

“It has to be embedded in a good concept more broadly,” he added, emphasizing that sleep, diet and conditioning are among the important components to go with the injections. “There’s no such thing as the one therapy that fixes everything.”

On a recent morning he treated not only Berg but a basketball player, a golfer, a Hollywood film executive and a former martial artist.

“The results were incredible,” Vijay Singh, the world’s former No. 1 golfer and a patient of Wehling’s, said in a telephone interview. “It’s like somebody just put oil all over your body. It lubes you up, and you’re able to move more freely, especially pain free.”

The question is how effective the treatment will prove in the long run.

Dr. Freddie Fu, a professor of orthopedic surgery at the University of Pittsburgh, has been critical of many such treatments, including PRP. He was slightly more optimistic about Wehling’s approach.

“The gimmick is, it’s your own body, it must be safe,” Fu said. “There has been some impressive research done already, and there is a good scientific fundament to do more research.

“However, before the FDA approves, more high quality independent trials have to be done in order to prove the effectiveness.”

Wehling comes from an old Rhineland family. His great-uncle was the archbishop of Cologne, and as a boy he met the future Pope Benedict XVI, Joseph Ratzinger. A father of two, Wehling plays keyboard in two bands, one jazz and one blues, giving off the vibe of a goofy-cool uncle, a little too enthusiastic to be completely hip.

“He’s very honest,” said Jeff Kwatinetz, president of the production company Prospect Park, who traveled from Los Angeles to receive the treatment on both shoulders. He was as impressed with Wehling’s bedside manner as the mobility he had regained in his joints.

“He hopes it can work, thinks it can work, but he’s not making any promises.”

KANSAS CITY, Mo. — Pablo Sandoval and Melky Cabrera turned the All-Star game into a Giant blowout.

Flashing their bright orange spikes and booming bats, the San Francisco sluggers keyed a five-run blitz against Justin Verlander in the first inning that sent the National League to an 8-0 romp over the American League on Tuesday night.

Cabrera homered and won the MVP award, and Giants teammate Matt Cain started a strong pitching performance for the NL in its most-lopsided All-Star victory.

Cain combined with Stephen Strasburg, R.A. Dickey, Aroldis Chapman and the rest of a lights-out staff on a six-hitter.

“San Francisco Giants show,” Matt Kemp of the rival Dodgers said during the game.

Ryan Braun, an All-Star again after his drug suspension was overturned last winter, doubled, tripled and made a fine catch in the outfield to help give the NL its first three-game winning streak in two decades.

Chipper Jones singled in his final All-Star at-bat at age 40 as the NL, under retired manager Tony La Russa, once again claimed home-field advantage in the World Series.

Teen sensation Bryce Harper had a shaky All-Star debut. Fellow rookie Mike Trout, only 20, showed off his dynamic skills.

The game was pretty much decided a few moments after it started.

Sandoval hit the first bases-loaded triple in All-Star history off Verlander, who couldn’t control his 100 mph heat. Cabrera singled and scored the first run, then hit a two-run homer against Matt Harrison in a three-run fourth.

“I don’t get many triples,” said the slow-footed Sandoval, known as Kung Fu Panda. “We had some fun with that in the dugout.”

Cabrera was flanked by his mom as he received his award.

“I was surprised for me, the MVP, but thank you the fans,” he said.

Rafael Furcal also hit a three-bagger, making the NL the first league with three in an All-Star game.

As the All-Stars returned to Kansas City for the first time since 1973, La Russa bid a fond farewell to the national stage in the city where he played for his first major league team.

Having retired after managing St. Louis to last year’s World Series title, La Russa became just the fourth inactive manager to skipper an All-Star team and improved to 4-2.

The NL boosted its advantage to 43-38-2 and won for just the third time in the 10 years the All-Star game has been used to determine home-field advantage in the World Series. La Russa’s Cardinals benefited from last year’s NL All-Star victory, with St. Louis winning Games 6 and 7 at home against Ron Washington’s Texas Rangers.

Jones, retiring at the end of the season, also had one last All-Star moment, pinch hitting in the sixth and singling just past second baseman Ian Kinsler and into right field. Jones chuckled as the ball rolled through.

“Whether you’re 19 or 40, we are all equals here,” Jones said during his pregame speech to the NL.

Harper, at 19 the youngest position player in All-Star history, had a shaky start when he entered in the fifth. The heralded rookie, wearing shiny gold shoes, didn’t flash a Gold Glove and lost Mike Napoli’s routine fly to left in the lights, allowing it to drop behind him for a single. He then caught Kinsler’s bases-loaded flyball to end the inning, earning cheers from the crowd of 40,933 at Kauffman Stadium, spruced up by a $250 million renovation that was completed three years ago.

Harper did draw a walk and tagged up on a long fly, but later got himself hung up in a rundown and tagged out.

Trout, among a record five All-Star rookies, had a nice showing against two very different pitchers. The Angels outfielder singled and stole a base against Dickey’s knuckleball, then drew a walk against Chapman and his 101 mph heat.

Cain pitched the 22nd perfect game in big league history last month. He didn’t have to be perfect in this one, allowing one hit in two innings for the win.

“For those guys to go out and score five runs in the first inning was definitely a little more relaxing for me,” he said. “But I still tried to stay focused.”

Cain was followed by 10 relievers, with Jonathan Papelbon getting the last out with a runner on third base.

Verlander had a puzzling outing. In games that count, he hasn’t allowed five runs in an inning since April 2010, according to STATS LLC. He became the first All-Star to give up a five-spot since Houston’s Roger Clemens in front of his hometown fans in 2004.

“It was pretty difficult for me to get the ball down today,” said Verlander, who admitted he approached this differently than a regular-season start.

In a 35-pitch inning, he threw five pitches clocked at 100 mph and another at 101.

“But I had fun,” he said. “That’s why I don’t try to throw 100 in the first inning. But this is for the fans. It doesn’t usually work out too well for me.”

A crowd clad in red, white and blue T-shirts cheered during pregame introductions for hometown star Billy Butler, who dropped his cap when he tried to wave it. Fans booed the New York Yankees’ Robinson Cano, who angered local fans when he bypassed Butler for Monday night’s Home Run Derby.

Not since Game 7 of Kansas City’s 1985 World Series over the Cardinals had the baseball world descended on the Royals’ ballpark, a rare 1970s beauty known for its 322-foot-wide fountain in right and the 105-foot-high scoreboard topped by a crown.

Cabrera, a former Yankee, singled with one out in the first and scored on a double to deep right by Braun, the reigning NL MVP.

Verlander threw six straight balls during consecutive two-out walks to Carlos Beltran and Buster Posey. Wearing shiny gold-and-orange spikes for the occasion, Sandoval sent a drive off the base of the wall in the right-field corner for a 4-0 lead.

He scored when Dan Uggla grounded to the shortstop hole and first baseman Prince Fielder failed to come up with Derek Jeter’s one-hop throw, leaving Uggla with an infield hit.

After Furcal tripled to right, pinch-hitter Matt Holliday singled for a 6-0 lead and Cabrera followed with a drive into the left-field bullpen.

Dickey, a first-time All-Star at 37, was given a big ovation. He pitched a one-hit sixth, hitting Paul Konerko on a shoulder with pitch.

Although he has a big league-best 12-1 record, Dickey was denied the start — possibly because of the difficulty of catching his knuckler. He brought along an oversized glove from Mets catcher Josh Thole that was used by Carlos Ruiz, who replaced Posey behind the plate in the sixth.

“I really appreciate the warm reception by the fans in Kansas City. Maybe a lot of them have heard my story,” Dickey said.

“It was definitely worth the wait,” he said.