SUNNYVALE, Calif. — Masaye Mitsunaga accidentally fell and injured her lower back while getting out of bed one morning last May. The Sunnyvale woman, then 97, was believed to have hit the metal frame of her bed.

The following day, the pain in her lower back was so severe that she was unable to move or get out of bed.

“I remember feeling pain a few hours after the accident. The pain got much worse, so my daughter took me to an emergency clinic the next morning,” said Mitsunaga, as translated from Japanese to English by her daughter Edith Oda.

“She was living in pain and didn’t want to eat,” Oda said.

Mitsunaga’s spinal fracture was caused by osteoporosis, a condition characterized by a loss in bone mass and density, and that usually affects older women.

Dr. Chiu Yuan performed a bone density test on Mitsunaga, who recently celebrated her 98th birthday. Yuan, Mitsunaga’s primary care physician, diagnosed her with osteoporosis.

After Mitsunaga visited the emergency clinic, X-rays were taken, and she was told to rest and take pain medication. She was informed that her condition would take six to eight weeks to improve. Six weeks after her fall, Mitsunaga was still in pain.

“After a few weeks, the pain was not any better, so my daughter took me to see another doctor,” Mitsunaga said.

So another daughter, Mae Mitsunaga, took her to see a specialist, neurosurgeon Marshal Rosario, MD, of Good Samaritan Hospital in San Jose.

Rosario said that prior to coming to the hospital, Mitsunaga had complained of pain in her hip and back. The doctor administered an X-ray, and discovered that Mitsunaga had a lumbar (L1) compression fracture.

Rosario took MRI scans to confirm whether Mitsunaga’s fracture was an old or new one.

Her MRI showed a subacute fracture, or a new fracture, which was treated with the Medtronic Kyphon balloon as an outpatient procedure.

Khyphoplasty involves creating an incision. Then an orthopedic balloon is guided into the fractured vertebral body. The balloon is inflated, reducing the fracture. In an attempt to achieve a reduction, two balloons are used. Once the fracture has been reduced, the balloons are deflated and removed.

Rosario said that needles are stuck into the fracture site, through the skin and the fracture bones, to try to elevate the fracture. He said that this is what causes people to bend over. The goal is to restore the patient’s height and alignment.

According to Rosario, the procedure entails filling the bone with plastic. While the plastic is initially quite malleable, it hardens like steel, Rosario said, and stabilizes the fracture.

“He used an adhesive that was injected into both sides of the spine to realign it. It heals and fuses the bone together. It’s like Super Glue. There was no pain,” said Oda, whose daughter is employed by Kyphon Products.

Rosario added that the procedure gets rid of back pain from fractures 70 to 90 percent of the time.

Mitsunaga, who was in and out of the hospital in one day, said that she was initially hesitant to have the surgical procedure done.

“My daughters explained to me what the doctor would like me to do. Because I am so old, I said ‘No.’ [But] they said this procedure would relieve my pain more quickly,” she said.

According to Oda, her mother was strong enough to work in the garden the day after the procedure.

Rosario said he saw Mitsunaga 10 days after her procedure, and she had no pain and had resumed normal activities.

Nearly a year after the procedure, Mitsunaga no longer has the debilitating pain in her back from the spinal fracture.

“I’m very grateful I had it done. It seems this was a long time ago because I don’t think about my back, as I have no pain,” she said.

Oda added, “She’s in better health than we are. She still goes on walks every day.”

While Mitsunaga, who has five children, five grandchildren and two great-grandchildren, has regular kidney check-ups, Oda said that her main health issue now is macular degeneration.

“She is losing her eyesight. She has peripheral vision. In the center, it’s blank,” Oda said.

Nonetheless, “she is hardly ever sick,” Mae Mitsunaga said, adding that her mother goes for daily walks around the neighborhood — “She goes up and down the block with her walker” — and that she also tries to eat healthily.

Mae Mitsunaga attributes her mother’s health and hardiness to her years as a migrant farmer.

“She did a lot of hard work on the farm,” she said, adding that her parents worked on strawberry farms.

Oda noted, “Mom is a very active person. She was a housekeeper and cleaned people’s homes in Los Altos.”

Mitsunaga was born in San Jose but was sent to attend school in  Japan, where she lived until she was 17 or 18. At that point, she moved back to the United States, where she got married and settled in San Jose.

In 1942, Mitsunaga and her family were sent to a concentration camp in Heart Mountain, Wyo.

“When the war started, we had to destroy Japanese books, records, etc., to show our loyalty to the United States,” Oda said. “We had to show that we were not sympathetic. When we went to camp, we did everything American.”

Mae Mitsunaga said she is grateful that her mother can enjoy her life following her treatment.

Oda added that her mother’s recent 98^th birthday celebration was all the more special following her treatment.

“She’s doing real well,” Oda said.

Heather Horiuchi contributed to this report.