The stem-cell injections new Knicks point guard Kemba Walker took in his left knee before last season are a strong indicator he is suffering from a type of arthritis that could greatly impact the 2021-22 season, according to a leading sports orthopedic surgeon.
The ballyhooed Walker acquisition was not made official Friday, on the first day of formal signings. Walker had to clear waivers after the Thunder bought out the final two years and $76 million left on his maximum contract Wednesday.
Walker also could be subject to physicals before the official signing — examinations that Dr. Wellington Hsu, professor of Orthopaedic Surgery at Northwestern University, recommends.
Walker, 31, played 43 of 72 games with the Celtics this season. He sat out the final two games of Boston’s first-round loss to the Nets because of left-knee trouble. The injections apparently didn’t solve his issue. In his first move as Celtics president, Brad Stevens traded Walker to the Thunder in June.
“He’ll always have the issue the rest of his career,’’ Hsu told The Post. “He’s not a spring chicken. He’ll have some type of lingering issue.”
The homecoming of Walker, who grew up in The Bronx and played at Rice High School in Harlem, could turn into a storybook tale, but it’s more likely his star power will be muted by knee maintenance.
Hsu said the stem-cell injections demonstrate severe wearing of the articular cartilage.
Injections of platelet-enriched plasma have been used as a remedy for that malady. But in the past four years, the stem-cell method has gained steam. In this procedure, Walker reportedly had stem cells taken from his hip and injected into his knee cavity.
“It can help pain and inflammation from arthritis,’’ Hsu said. “But the articular cartilage that lines the bone of the knee is wearing down.’’
That condition doesn’t bode well for Walker to return to All-Star form. The former Connecticut point guard, who won an NCAA title with the Huskies in 2011, was an All-Star four straight seasons, from 2016-20, before last season’s decline.
While he averaged 19.3 points, 4.9 assists and 4.0 rebounds, he shot just 42 percent — and an average-for-him 36 percent from 3.
“It’s huge,’’ Hsu said. “I’ve published many papers on how that knee problem is a really impactful injury for a basketball players more than soccer, football, hockey. Wear-and-tear, especially when you’re a guard and need lateral movement, that’s when the knee swells up the most. It’s very impactful for any guard — point guard or shooting guard.”
The Thunder were essentially given draft picks to obtain Walker’s contract with an idea of flipping him in another trade. There was no market, so Oklahoma City bought him out earlier this week. The desperate Knicks, striking out on other targets, brought Walker home on a modest deal that could still be reworked but is believed to be for the rest of the Knicks’ cap space ($8 million) with possibly a second-year option.
“Any GM would look at history of arthritis knee injuries in guards and would know that he’s on a game count or minutes count,’’ Hsu said. “He’s not going to be available all the time. I don’t know if you want a max salary on a guy like that, especially if you’re in your 30’s. If he was in his 20’s, there’s chance he can regenerate some of that tissue over time. It’s going to be dicey on how much he plays.’’
Hsu went as far as to say articular-related arthritis is worse than ACL surgery.
“An ACL injury, that ligament will heal and be as strong as it was for basketball,’’ he said. “That cartilage wear and tear is more risky, more concerning.’’
The Knicks did announce Friday the signings of draft picks Quentin Grimes (25th) and Miles McBride (36th). Grimes will make the rookie scale of $1.8 million.