At age 91, Josephine Calvert has simple goals: return to needlepoint, clean her house – and avoid a stroke.

So when recent tests showed she needed a heart valve replacement, she didn’t hesitate to sign up for surgery.

“I didn’t know if I’d come out of it because of my age, but somehow there is a strength lurking in me to keep on going,” she said at her apartment in Manhattan’s Peter Cooper Village.

Calvert is among a growing number of New Yorkers over 90 having surgery – a trend doctors say has forced them to make changes in how they operate.

Two decades ago, almost no one in their 90s had surgery in New York, local surgeons say. Now, about 5% of their surgical patients are over 90.

“In the past, people didn’t get old enough that they needed surgery in their 90s because they died of other diseases,” said Aubrey Galloway, chairman of cardiothoracic surgery at NYU Langone Medical Center.

For Morris Greenberg, 91, of Glendale, Queens, delaying a hernia operation meant living in pain.

“It was bothering me, and I didn’t want to be extra-careful about everything I did,” he said.

He decided to go under the knife in September at Beth Israel Medical Center in Manhattan, where Dr. Martin Karpeh used local anesthesia to avoid a higher risk of infection.

“If they’ve lived to 90, they are in fairly decent health, so the probability of living another 10 years is reasonable,” Karpeh said.

At New York Presbyterian, instead of opening the chest of their oldest patients for heart surgery, doctors often rely on a less invasive procedure that involves inserting a catheter through a small incision to replace valves.

“It’s a whole new arena of therapy for this group of patients,” said Karl Krieger, vice chairman of the department of cardiothoracic surgery, who recently operated on a 98-year-old.

“We know 100-year-olds that will require surgery in the next year or two. This might be an option for them,” he said.

The over-85 set is the fastest-growing segment of the city’s population, so the spike in surgery isn’t likely to fade away soon, according to Bobbie Sackman, director of public policy at the Council of Senior Centers and Services.

“We are watching such a longevity boom, so we are going to see even more people coming into the medical system in their 90s looking for surgery,” she predicts.