MEDIA CONTACT: Mike Goodkind, (650) 725-5376 or goodkind@leland.stanford.edu

FOR COMMENT: Huy M. Do, MD, (650) 723-6767 or huymdo@stanford.edu; Stuart Goodman, MD, PhD, (650) 723-7072 or goodbone@stanford.edu; and Amy Ladd, MD, (650) 723-6796 or alad@leland.stanford.edu

EDITORS, REPORTERS PLEASE NOTE: Color photos/scans of the patient playing piano for Dr. Ladd are available on request. 

STANFORD-When 90-year-old Maude Oosterhof splintered her wrist in a fall in the garage of her Menlo Park, Ca., home, she expected a long recovery in a cast and worried that her fragile bones might never mend.

She was surprised when Stanford reconstructive surgeon Amy Ladd, MD, said she could "paste" Oosterhof's wrist back together with an injectable, quick-setting bone cement.

Now, nearly 13 months later, Oosterhof's wrist is not only mended, but she can play the piano, a practice she had abandoned years ago. "It's good exercise, and I even enjoy my mistakes," she said. Oosterhof's repaired wrist also gives her the ability to write notes, cook meals and work a bit in her garden.

Ladd, associate professor of functional restoration, is one of a rare but increasing number of physicians who use needles and high-tech cements to fill in gaps and strengthen injured bones in wrists, hips and spines. Other Stanford doctors using bone cements include interventional neuroradiologist Huy M. Do, MD, assistant professor of radiology, who uses a cement to repair spines; and Stuart Goodman, MD, PhD, professor and chief of the division of orthopaedic surgery, who uses bone cement for patients who might otherwise require complex hip reconstruction for avascular necrosis (bone death). 

The relatively quick, less invasive procedure is often performed under regional anesthesia and offers significant pain relief within hours or days - seemingly too good to be true to patients who may have been severely incapacitated by their injury. 

"I was awake and talking to the doctors the whole time," said Oosterhof. The alternative for her would have been a lengthy, major surgical procedure under general anesthesia that would require harvesting some of her own bone as a graft.

Although Ladd's patient was in her 90s, the procedure is "especially useful for relatively young patients - those in their 40s - who want to remain active without facing a long period of recovery and relative inactivity," said Goodman, who has been performing the procedure for about a year. "For them, the short hospital stay and rapid recovery are tremendous advantages."

Ladd and Goodman use a recently developed product called Norian SRS (Skeletal Repair System), which they say has the compelling advantage of allowing the body to replace the cement with new bone growth over time. That's because the cement, a special formula of calcium phosphate - the naturally occurring mineral of bone - is biocompatible and defers to the body's natural inclination to repair itself over time.

But cement treatments are not for everyone, say the doctors who use it. Goodman notes that repairs with SRS don't handle the strain of torsion as well as healthy bone alone. Some patients with large or complicated injuries will still need implants or pins - placed during more invasive surgery - to handle the twists and turns that healthy human bone handles so effectively.

However, when natural bone has taken over and remodeled the SRS, a process that can take several years, the torsion strength approaches that of natural bone, said Goodman.

In contrast, Do uses a different cement to fill and support fractures in spinal vertebrae. The material he uses, polymethylmethacrylate or PMMA, is a chemically synthesized cement. While PMMA doesn't stimulate replacement bone growth, "tests have shown that the cement has strength and stress-resistance that is stronger than bone," said Do. PMMA has been available commercially for 30 years, said Do, "and has a very good track record in terms of strength, stability and biocompatibility." These features are important to the 750,000 people who each year fracture a vertebra. Some 150,000 of these patients require hospitalization, and many suffer from severe pain when standing or walking.

In a procedure known as percutaneous vertebroplasty, Do and his colleagues insert a needle into the spine to reach the fracture site. In its initial liquid form, PMMA fills any cavities or spaces within the damaged bone. After an hour or two, the liquid hardens into a body-friendly cement.

According to Do, some patients who have difficulty standing due to the pain of the fractured vertebrae are able to walk out of the hospital the same day after vertebroplasty, and almost all experience significant or complete pain relief within 24 hours.

Do notes that many of his patients are elderly women with osteoporosis whose weak bones are particularly susceptible to fracture. Once bedridden by an injury, they find it difficult to regain strength and mobility. Because vertebroplasty is performed under local anesthesia and typically takes only a few hours to complete, it offers patients a chance to resume a normal lifestyle within one day of treatment. While vertebroplasty does not protect against subsequent fractures in other vertebrae, the minimally invasive nature of the procedure lends itself to repeated treatments if necessary.

Vertebroplasty can also be effective for people whose spines have been weakened by metastatic cancer, chronic steroid usage and a variety of bone diseases.

"Anybody with a compression fracture that is painful is eligible," said Do. However, it is necessary to be certain that the patient's back pain is due to a fractured vertebra and not some other compounding factor, he adds. Do turns away about one-third of his potential patients for that reason, referring them instead to Stanford's pain management clinic for treatment. Additionally, patients with vertebral fractures in which the spinal canal itself is compromised are not good candidates for vertebroplasty.

Despite the dramatic and lasting effects of vertebroplasty, it is offered at only a few institutions across the country.

"A lot of people don't know about this yet," said Do. "I think the key is to get the word out to patients because until now, the only treatment option available was rest and pain medication." 

Do was the first to perform vertebroplasty at Stanford. He arrived at Stanford in July from the University of Virginia, where he was trained to perform the procedure by its American pioneers, Mary E. Jensen, MD, and Jacques E. Dion, MD. Since July, 14 patients have undergone 22 bone strengthening procedures at Stanford, and according to Do, all have experienced significant or complete pain relief, significantly increased activity levels and decreased pain medication use. Studies at the University of Virginia with a larger number of patients and long-term follow-up indicate that these gains are durable, with an overall success rate of 80 percent.

Do's colleagues in the procedure are Barton Lane, MD, professor of radiology, and Michael Marks, MD, associate professor of radiology.

Percutaneous vertebroplasty is covered by most private insurance companies and in some areas, by Medicare. Recently, Do successfully urged the Medicare carrier for Northern California to agree to cover this procedure.

The use of bone cements for repairing wrists is FDA approved; the use as an adjunct for more complex hip reconstruction surgery is still in a research phase in this country, although commercially available worldwide. Select patients who join research studies conducted by Ladd and Goodman are eligible for the implantation of SRS, which may be available for general fractures by the end of the year 2000. Many other bone graft substitutes that resemble naturally occurring bone materials are in development and under research nationwide.

Ladd has performed six wrist repairs using SRS and has reviewed the results of more than150 of these procedures performed in an FDA-controlled study. She presented these results to an FDA panel in 1998, which led to the material's approval later that year. Goodman has used SRS cement to help three patients undergoing hip procedures in the past year as part of a randomized study. A recent biomechanical study by Goodman and colleagues suggests that the cement may be of use in stabilizing hip fractures as well.

SRS is manufactured by Norian Corp. of Cupertino, Calif. PMMA is marketed commercially by several manufacturers nationwide.

For further information about wrist repair, contact Ladd at (650) 723-6796 or alad@leland.stanford.edu. For minimally invasive hip reconstruction for avascular necrosis, contact Goodman at (650) 723-7072 or goodbone@leland.stanford.edu.

For more information about vertebroplasty, contact Do at (650) 723-6767 or huymdo@stanford.edu. 
 

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