Percutaneous vertebroplasty is a minimally invasive,
fluoro-scopicallyguided procedure used in the treatment of painful
verte-bral body compressionfractures. Originally developed in
it has gainedacceptance in the United States over the past 6 years,
primarily as a therapyfor painful osteoporotic compression
fractures unresponsive to medicalregimens.
Currently, the major teachers, researchers, andpracti-tioners of
vertebroplasty are radiologists; however, recent interestfrom
orthopedic surgeons and neurosurgeons has spurred attempts to claim
it asa "surgical" procedure, necessitating an operating room and
generalanesthesia. The purpose of this article is to stimulate
interest invertebroplasty among radiologists by familiarizing them
with all aspects ofthis new procedure, including indications,
risks, tech-nical aspects, andoutcomes.
is an Associate Professor of Radiology with a
jointappointment in the Department of Neurosurgery, and the
Director ofInterventional Neuroradiology at the University of
Virginia Health SciencesCenter, Charlottesville, VA.
Each year, more than 700,000 verte-bral body fractures,
secondary toosteo-porosis, are diagnosed in the U.S. population,
that result in 115,000hospi-tal admissions. The lifetime risk of a
vertebral body compressionfracture is 16% for women and 5% for men;
and the incidence of osteoporoticfractures is anticipated to
increase four-fold world-wide in the next 50 years.
Other causes of painful compression fractures include
malignantinvolvement of the spinal column (metastases, myeloma, and
lymphoma),hemangioma, and vertebral osteonecrosis. In addition to
pain, spinal columninstability may also be present.
Approximately 84% of vertebral body compression fractures are
asso-ciatedwith pain, leaving patients bed-ridden and dependent on
analgesics. Bone lossis accelerated by immobilization, thus
compounding the prob-lem. In addition,these disabled indi-viduals
are more susceptible to pneumonia, deep venousthrombosis, and
pulmonary embolism. In most patients, the pain lasts an averageof 4
to 6 weeks. However, there is a sub-group of affected persons in
whom thepain persists for months or never fully subsides. Patients
with fractures havebeen shown to be more dependent in activities of
daily living (ADLs), andsuffer from weight loss, decreased exercise
tolerance, and depression.
Regardless of etiology, treatment for compression fractures has
been largelyconservative and directed toward pain control, usually
consisting of narcoticanalgesia, bedrest, and back bracing. For
osteoporosis, current preventativedrug regimens, including hormonal
replacement therapy, biphosphonates, andcalcitonin, often are not
prescribed until the disease has been diagnosed bythe presence of a
In recent years, several reports of dramatic pain relief
following thepercutaneous injection of an acrylic "cement,"
polymethylmethacrylate(PMMA), into osteoporotic or neo-plastic
compression fractures have beenpublished.
In the late 1980s, Galibert and colleagues 1described "percutaneous
vertebroplasty" in the treatment ofcompression fractures associated
with hemangiomas and metastatic disease. Theprocedure involved the
percutaneous puncture of the fractured vertebral body,followed by
injection of PMMA to provide bone augmentation and prevent
fur-thercollapse. The "internal casting" of the trabecular
fractures resultedin pain relief and vertebral stabilization,
allowing patients to mobilizequickly and reducing their need for
Patient selection criteria
Patients considered for vertebro-plasty are those experiencing
moderate tosevere pain from a radiologically confirmed compression
fracture that isunresponsive to best medical therapy, as determined
by the referring physician.
Associated major disability, such as inability to walk or
performADLs, is almost always present. In our experi-ence, the
patients who bestrespond to treatment are those with fractures
<12 months in age with a mildto moderate degree of collapse.
Fractures older than 12 months that showincreased uptake on a bone
scan or recent further col-lapse often respond aswell.
Long-standing fractures, multiple fractures, and vertebra
plana,particularly when associated with kyphosis and facet
hypertrophy, are lesslikely to show improvement.
On examination, point tenderness on palpation over the spinous
process ofthe affected vertebrae is common. Many patients complain
of pain that radiatesalong the corresponding der-matome, but any
focal neurological deficits needcomplete evaluation to exclude
burst fracture, significant retro-pulsedfragment, infection, or
other pathology, such as a herniated disc. Thisinformation is
obtained easily with computed tomography (CT) and/or
magneticresonance (MR) imaging. MR has the advantage of
demonstrating edema associatedwith acute or suba-cute fractures,
which is particularly helpful in a patientwith multiple frac-tures
of uncertain age. Bone scanning is also useful indetermining active
frac-tures, but hyperacute fractures may give a falsenegative
response. In addi-tion, severe facet disease may appear as
vertebralbody uptake if SPECT scan-ning is not performed.
There are other selective indica-tions for vertebroplasty, such
asnon-traumatic unstable fractures involving the anterior column
only, whereante-rior wedging of the vertebral body occurs in the
Another indication is for reinforce-ment of an affected
vertebraprior to a posterior surgical stabilization proce-dure.
Occasionally,prophylactic reinforcement of adjacent osteoporotic
vertebral bodies before anintradiscal fusion procedure is
Treatable pathologies include osteo-porosis (both
steroid-induced andage-related), myeloma, metastatic disease, and
hemangioma of the vertebralbody. Relative contraindications include
spinal canal compromise >20% byretropulsed fragments, >90%
vertebral body col-lapse, back pain for >1year, and tumor
extension into the epidural space. Absolute contraindicationsfor
ver-tebroplasty include: patients clearly improving on medical
therapy;osteo-myelitis; uncorrected coagulopathy; or as prophylaxis
in osteopenicpatients with no evidence of fracture and no planned
Vertebroplasty is performed in a standard angiography suite
although in some instances the needle is placed underCT guidance.
Using a biplane fluo-roscopy unit, if one isavailable, will
decrease the procedure time. Poor quality C-arms are to beavoided
as the image quality is usually too poor for adequate visualization
ofthe required landmarks and cement flow.
The patient is placed in the prone position on the angiography
table andattached to the appropriate physio-logic monitoring
devices. Continuousmonitoring and dedicated nursing support during
the procedure are absolutelynecessary. Conscious seda-tion using
fentanyl and midazolam is sufficient formost patients, although
those in severe pain may require gen-eral anesthesia.
The pedicle to be punctured is iso-lated under anterioposterior
(AP) andlateral fluoroscopy, and the skin is marked. After sterile
preparation of thepuncture site, the skin, soft tissues, and
periosteum of the targeted pedicleare anesthetized using 7 to 10 mL
of 0.25% bupivicaine.
A small,horizon-tal skin incision is made, and a stan-dard 11G bone
biopsy needle isadvanced under fluoroscopic guidance into the
vertebral body via thetranspediculate approach (figure 1). A 13G
needle may be used for small or thinpedicles. Frequent visual
checks under AP and lateral fluoroscopy ensure thatthe needle path
remains within the pedicle and not outside of it. The tip
ispositioned in the anterior one-third of the vertebral body on the
lateralprojection. On the AP view, the needle should take a lateral
to medial course,with the tip ultimately posi-tioned in the
mid-hemivertebra to mid-line. Thecloser to the midline, the more
likely the cement will be distrib-utedthroughout the entire
vertebra, making a contralateral puncture unnec-essary.This midline
position can be achieved by initially targeting the pedi-cle inthe
more oblique "scotty-dog" position (figure 2), but the
pedicularcortex may be less obvious.
Once in position, needle tip location outside of major venous
structures isconfirmed by injection of 3 to 5 mL of diluted
contrast material. This"verte-brogram" outlines the trabecular
space, the basivertebralplexus, and the sur-rounding internal and
external epidural venous plexus. Ifthe needle tip is directly
within a major vertebral vein, then it may beadvanced more
anteriorly or plugged with gelfoam or a thick cement
slurry.Although the consistency of cement is different from that of
contrast, animage from the verte-brogram can be a useful reference
when paravertebral orepidural venous filling is suspected (figure
Once appropriate needle positioning is obtained, the PMMA is
prepared forinjection. The polymer powder is mixed with an
antibiotic powder (usuallytobramycin) and sterile, pure bar-ium
sulfate (for opacification). The liq-uidmonomer is added until a
material with a thin "cake-glaze"consistency is created. This
material is then injected into the vertebra underfluoroscopic
Frequent checks in both planes ensurethat the material remains
within the vertebral body without migrating into thesurrounding
venous plexus. If cement leaches across an endplate fracture,
asmall amount of material is allowed to layer on the disc side;
however, largeamounts of PMMA in the disc space may act as a wedge,
resulting in fracture ofthe adja-cent body. If the injection
becomes dif-ficult or cementpreferentially flows to a vein, the
needle should be reposi-tioned posteriorly.Persistent venous
filling is an indication to cease injec-tion, lest thematerial
migrate to the inferior vena cava or azygous system with
resultantpulmonary embolization. Injection is terminated when
adequate filling of thevertebral body is obtained, or when the
cement border reaches the posteriorquarter of the vertebral body.
The contralateral hemisphere is treated in asimilar manner, if
necessary (figure 4).
After the procedure, all patients are observed in the supine
position for 1hour, followed by sitting or standing as tolerated.
New chest or back pain, orneurological dysfunction is evaluated
immediately so appropriate treatment canbe instituted. Ambulatory
patients are discharged to the care of an adult. Painmedication may
be taken as needed, but patients are encouraged to limit druguse so
efficacy of the treatment can be determined. Patient follow-up,
bydirect contact or telephone, is made within 48 hours.
The minor or transient complication rate in osteoporotic
fractures is 1% to3%, and as high as 10% in metastatic lesions.
Fortunately, thepermanent complication rate for all lesions is
<1%. Potential complicationsinclude migra-tion of cement into
the epidural venous plexus or leakage througha fracture into the
canal resulting in spinal cord or nerve-root compression;cement
embolization to the lungs; fracture of the pos-terior elements
orpedicles; rib fracture; hemorrhage; and infection. Ability to
recognize andcare for these complica-tions, including emergency
surgical support, isessential.
Complications can be avoided by appropriate patient selection,
use ofout-standing fluoroscopic equipment and strict aseptic
technique, properopacifi-cation of cement, fluoroscopically
con-trolled injection, and awarenessof areas that may be difficult
to see. If visualiza-tion of the material isinadequate, the
procedure should be terminated.
Review of the literature shows sev-eral small or moderate-sized
series oftreated patients with good clinical out-comes, although no
large seriesevalu-ating the durability of vertebroplasty has been
published to date.Deramond and colleagues
reported 80 patients with rapid andcomplete pain relief in >90%
of osteoporotic cases. Follow-up ranged from 1month to 10 years,
with evidence of prolonged analgesic effect. We notedsimilar
results, with acute pain relief in 90% of 29 treated patients,
asevidenced by their verbal expression of perceived pain and
anal-gesic use. 2Statistically significant differences in analgesic
use and patient mobilitypre- and post-treatment has also been found
in 84 patients with 159osteoporotic fractures followed for up to 3
years (ME Jensen, unpublisheddata, 1997).
The percentage of responders among patients treated for
metastatic diseasemay be less than other patient groups. In
Deramond and coworkers'
series of 101 patients with metastatic disease, 80% demonstratedan
imme-diate significant analgesic effect and improvement in patient
qualityof life. Weill and colleagues
treated 37 patients with 52metastatic lesions and found 73% with
clear improvement, defined as a 50%decrease in narcotic dose or
change to a non-narcotic med-ication, and abilityto walk.
Durability of results was also positive; 73% of patients
hadpersistent pain relief at 6 months and 65% at 1 year. Recurrent
pain wasassociated with new metastases. One complicating factor in
treatment analysiswas the concomitant use of radiation and
chemotherapy in some patients, makingit difficult to ascertain the
effect of each therapy upon the overall painsyndrome.
Percutaneous vertebroplasty is a promising new therapy in the
treatment ofpainful compression fractures refractory to
conservative treatment. Thisprocedure significantly reduces pain
and restores mobility in the majority ofappropriate candidates,
allowing patients to return to their previous qual-ityof life
quickly. Radiologists are best suited to perform this procedure
giventheir training in fluoroscopically guided percutaneous
techniques and theirhigh-quality imaging equipment. We strongly
urge that every radiology grouphave at least one physician trained
to perform vertebroplasty, as demand forthis procedure is certain
to grow in the next several years. AR
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