New procedure uses bone
cement to stabilize spinal fractures and alleviate pain
BY KRISTA CONGER
By injecting liquid bone
cement directly into the cracks and crevices of a broken
vertebrae, interventional neuroradiologists at Stanford
are able to strengthen the fractured bone and provide
permanent pain relief to people suffering from
excruciating spinal fractures. Many patients for whom
traditional methods have proven ineffective have
experienced a dramatic improvement within 24 hours of the
new treatment, researchers say.
"It's kind of like
getting a cavity filled when you go to the dentist,"
said Huy M. Do, MD, of the minimally invasive procedure
known as percutaneous vertebroplasty. But the pain
associated with a fractured vertebrae makes a toothache
seem trivial.
According to Do, an
assistant professor of radiology at Stanford, about
750,000 new vertebral fractures occur each year in the
United States, and about 115,000 of them result in
hospitalization. The traditional treatment methods of bed
rest, pain medication and back bracing are frequently
insufficient at relieving the often debilitating pain
associated with about 80 percent of the cases and which
prevents some sufferers from leaving their beds.
In percutaneous
vertebroplasty, Do and his colleagues insert a needle
into the spine to reach the fracture site. They then
inject a bone cement called polymethylmethacrylate
(PMMA). 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.
"Tests have shown
that it has strength and stress-resistance that is
stronger than bone," said Do. This super-strong
compound is able to shore up the fragile bone and support
the broken vertebrae.
PMMA has been used as a
bone replacement for many years in the United States, but
percutaneous vertebroplasty has the advantage of being a
minimally invasive procedure that does not require open
surgery. According to Do, a typical treatment is
performed under conscious sedation and local anesthetic
on an outpatient basis, making the improvements all the
more dramatic. 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, he said. "It's
really gratifying when these patients start to feel good
again," said Do.
Do's colleagues in the
procedure are Barton Lane, MD, professor of radiology,
and Michael Marks, MD, assistant professor of radiology.
Do's arrival at Stanford
in July from the University of Virginia marked the first
time Stanford began to perform vertebroplasty. Do was
trained to perform the procedure by its American
pioneers, Mary E. Jensen, MD, and Jacques E. Dion, MD.
Since July, seven patients have undergone the bone
strengthening procedure at Stanford, and all seven have
experienced complete pain relief. Studies at the
University of Virginia with a larger number of patients
indicate an overall success rate of 80 percent.
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."
In the face of such
gradual and uncertain improvement, vertebroplasty may
seem like a godsend to many sufferers. Most of the
patients treated at Stanford are elderly women with
osteoporosis. Their weak bones are particularly
susceptible to fracture, and once bedridden by an injury,
it is difficult for them to regain their 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.
Although osteoporotic
women have been the primary beneficiaries, vertebroplasty
can also be effective for people whose spines have been
weakened by metastatic cancer, chronic steroid usage or
other types of bone disease.
"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 vertebrae 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 alternative treatments.
Additionally, patients with vertebral fractures in which
the spinal canal itself is compromised are not good
candidates for vertebroplasty.
Percutaneous
vertebroplasty is covered by most private insurance
companies and is covered in some areas by Medicare.
Do plans to discuss the
treatment with other Stanford physicians during
neurosurgical grand rounds October 15. to encourage them
to consider vertebroplasty for their patients with
painful vertebral fractures.
For more information about
vertebroplasty, contact Do at 723-6767 or
huymdo@stanford.edu. SR
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