"Miss Lillian" Carter, the president's 82-year-old mother, fell and broke her hip yesterday, and a team of Georgia doctors performed a major, two-hour operation to repair it.

Her surgeon and physician, Dr. John H. Robinson III, said, "Miss Lillian withstood the operation extremely fine." He said "she is in good condition" and her doctors "do not anticipate any unusual problems."

The break nonetheless seemed to be a serious one which could keep her off her feet, except on crutches or a walker, for two or three months, or even longer if there are complications.

Hip breaks are always a serious matter. And they are particularly so for older persons with brittle bones and an uncertain response to the possible complications of extensive surgery.

An operating team under Robinson and an orthopedic surgeon who was not identified repaired the broken hip with a metal pin and a plate.

They began preparing for the operation at the Americus and Sumter County Hospital at 4 p.m. and completed it around 6:30 p.m. Miss Lillian was expected to remain in the hospital's recovery room for one or two hours, and the hospital said there would be no further statement until 10 a.m. today.

The president's brother, Billy, Billy's wife, and his sister Gloria Carter Spann, were at the hospital. Robinson kept in touch with the president during a day of campaigning in Ohio and Pennsylvania, and again after the operation.

The president began a suburban Philadelphia appearance by asking the audience to say a prayer for his mother. Then he joked that he did not know whether she had been surfing or skate-boarding when she fell.

He is expected to fly to see her either today or tomorrow.

"She's in very good spirits -- she's just her same perky self," Jo Collins, chief nurse at the hospital, said of the president's mother early yesterday afternoon. She was said to be "resting comfortably" after being given pain-easing medication.

On the campaign trail with the president, press secretary Jody Powell said Mrs. Carter sent her son a message saying he shouldn't worry and she would talk to him "when I get through messing around with the doctors."

The accident happened at about 8 a.m. at Miss Lillian's home in Plains, when she slipped on a rug as she stood up to turn on a television program.

She was alone but managed to call for help. She was taken to the nearby hospital in Americus, where administrator James Griffith called the break "just a fractured hip which could be repaired by surgery."

But Robinson called it a break of the right side of the hip, at the point where a large protrusion called the great trochanter -- the bump on the side of the hip -- meets the head of the femur or upper leg bone.

"That's usually a bad break," said a Washington surgery professor with no link to the case.

"If all goes well and she lucks out and there are no complications, she may be up in a chair in a day or two. But she probably wouldn't be able to leave the hosptial for 10 to 14 days, and it could be six to 12 weeks before she can really bear any weight.

"How long healing takes really depends on the more exact nature of the break, and the exact kind of repair her surgeons choose."

Total healing of a hip fracture can take as long as eight to 12 months. And the picture can be worse if any serious complications -- such as pneumonia or blood clotting -- develop.

"Most patients, even older patients, do well today," the Washington surgeon commented. But some patients are left with a permanent deformity and limp.

Born in Richland, Ga., 20 miles from Plains, on Aug. 15, 1898, Mrs. Carter earned a nursing degree at Grady Memorial Hospital in Atlanta.

In 1923 she married peanut farmer and businessman James Earl Carter Sr. After his death she became an Auburn University fraternity housemother and worked in a nursing home.

In 1966 she joined the Peace Corps and served in a clinic near Bombay, India, for two years as that corps' oldest volunteer.

The president sent her to Yugoslav President Tito's funeral last May as one of his representatives, and she has spent much of his term making other appearances and uttering quotable observations, often caustic, that have kept her before the public.