In Case Viagra No Longer Does The Trick
STANFORD, Calif., Jan 12, 2000 (BW HealthWire) -- When 90-year-old
Maude Oosterhof splintered her wrist in a fall in the garage of her
Menlo Park, Calif., 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 than 150 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.
Note to Editors: Color photos/scans of the patient playing piano for
Dr. Ladd are available on request.
Copyright (C) 2000 Business Wire. All rights reserved.
Distributed via COMTEX.
-0-
CONTACT: Stanford Medical Center
Mike Goodkind, 650/725-5376 (Media)
goodkind@leland.stanford.edu
or
Huy M. Do, MD, 650/723-6767
huymdo@stanford.edu;
Stuart Goodman, MD, PhD, 650/723-7072
goodbone@leland.stanford.edu
Amy Ladd, MD, 650/723-6796
alad@leland.stanford.edu
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