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Neto PP, Kihara EN, Fontoura EAF, Andrioli MS, Andrade Junior A, Romaldini H, Nóbrega JL
ORIGINAL ARTICLE
Percutaneous vertebroplasty with polymethylmethacrylate
Analysis and results in 57 treated patients
Vertebroplastia percutânea com polimetilmetacrilato
Análise e resultados de 57 pacientes tratados
Pascoal Passarelli Neto1, Eduardo Noda Kihara2, Emilio Afonso França Fontoura3, Mario Sergio Andrioli4, Ary de
Andrade Junior5, Helio Romaldini6, João Luiz Nóbrega7
ABSTRACT
Objective: The aim of this study is to show percutaneous
vertebroplasty as a safe procedure for pain management in diseases
such as osteoporosis, benign and malignant spinal tumors, whether
primary or secondary, by relieving localized pain and strengthening
vertebral body structure. Methods: Percutaneous injection of
polymethylmethacrylate under high-resolution fluoroscopy, inside
the fractured vertebral body, rebuilding and stabilizing its structure
with little sedation and local anesthesia. Results: Ninety-five
percent of patients felt immediate pain relief and recovered
movement and walking. We verified that only one patient presented
mild and transient respiratory insufficiency, probably due to
microembolism. No other complications were observed. Three
patients returned for another vertebroplasty in vertebral bodies
close to those previously treated. Conclusion: Percutaneous
vertebroplasty is a safe and efficient procedure in pain and
immobility management associated with vertebral compression
– fractures that require much pain relief and stability.
Injeção percutânea de polimetilmetacrilato, sob visão
fluoroscópica de alta resolução, dentro do corpo vertebral fraturado,
refazendo sua estrutura de sustentação, ou seja, recuperando sua
função, com leve sedação e anestesia local. Resultados: Em 93%
dos pacientes houve alívio imediato da dor com recuperação da
movimentação e da própria deambulação. Constatamos um único
caso de insuficiência respiratória leve e transitória, provavelmente
conseqüente à microembolia. Não houve outras complicações.
Três pacientes retornaram para nova vertebroplastia em corpos
vertebrais vizinhos aos anteriores, devido a novas fraturas; os
demais pacientes permaneceram estáveis em acompanhamento
ambulatorial sem apresentar novos colapsos vertebrais.
Conclusão: Vertebroplastia percutânea é um procedimento seguro
e eficiente no tratamento da dor e da imobilidade associadas à
fratura da coluna vertebral; visa acabar com a dor e a instabilidade
dos fragmentos intracorpóreos.
Descritores: Osteoporose; Vertebroplastia; Fratura de corpo
vertebral
Keywords: Osteoporosis; Vertebroplasty; Vertebral fracture
RESUMO
Objetivo: Mostrar uma nova técnica de tratamento percutâneo
para ablação da dor devido a fraturas ocasionadas por doenças
como a osteoporose, tumores benignos e malignos primários e
secundários da coluna vertebral, eliminando o quadro álgico
localizado e reforçando a estrutura óssea intracorpórea. Métodos:
INTRODUCTION
Percutaneous vertebroplasty consists of injecting
polymethylmethacrylate (PMMA), an acrylic cement,
through a needle in the interior of a fractured vertebral
body to manage pain and strengthen its bone structure.
Pain related to fracture by vertebral body
compression affects from 700,000 to 1 million
Radiology and Intervention Neuroradiology Service - Hospital Albert Einstein - São Paulo - 2004.
1
Neurosurgeon. Full Member of the Sociedade Brasileira de Neurocirurgia and Effective Member of the European Federation of Spine Surgery.
2
Neuroradiologist at the Intervention Neuroradiology Service of the Hospital Israelita Albert Einstein.
3
Neurosurgeon. Head of the Neurosurgery Service at Complexo Hospitalar do Mandaqui.
4
Neurosurgeon and Neuroradiologist of the Hospital Israelita Albert Einstein.
5
Internal Medicine specialist and Cardiologist. Coordinator of the course Physical Therapy in Internal Medicine at UNIFESP- Escola Paulista de Medicina.
6
Chest physician. Adjunct Professor at UNIFESP - Escola Paulista de Medicina.
7
Rheumatologist, Internal Medicine specialist and Intensivist.
Corresponding author: Pascoal Passarelli Neto - Av. Albert Einstein, 627 - 10º andar - sala 1013. CEP 05651-901 - São Paulo (SP), Brazil - e-mail: [email protected]
Received on April 15, 2004 – Accepted on August 20, 2004
einstein. 2004; 2(4):278-81
Percutaneous vertebroplasty with polymethylmethacrylate Analysis and results in 57 patients treated
individuals per year in the U.S.(1) and its major cause is
osteoporosis. Primary osteoporosis caused by
demineralization and resulting in age-related bone loss
accounts for approximately 85% of vertebral
compression fracture and affects roughly 200 million
women aged over 50 years. Secondary osteoporosis
observed in patients taking steroids, anticonvulsants,
chemotherapeutic agents and heparin, as well as in
vertebral tumors, accounts for 15% of vertebral
compression fractures. Approximately 20-30% of
patients with vertebral compression fracture observed
in plain radiographs present restricted daily activities
and pain intensity 3 and 4, according to the verbal scale
(VS) - McGill-Melzack scoring system(2) (table 1).
Table 1. Verbal scale - McGill-Melzack Scoring System 0-6
0
1
2
3
4
5
-
No pain
Mild pain
Troublesome pain
Severe pain
Very severe pain
Excruciating pain
The traditional treatment for vertebral compression
fracture is analgesic medication, bed rest and bracing. Surgical
treatment is performed in cases of neurological deficit
related to compression of the nerve root or spinal cord(3).
Approximately one third of patients with vertebral
compression fracture do not respond to conservative
treatments, resulting in prolonged inactive periods and
increased bone mass loss with higher risk of new fractures(4).
In 1987, Galibert et al.(5) were the pioneers in using
acrylic cement in a C2 vertebral body with hemangioma,
in a 50-year patient who suffered from cervical pain.
This study aimed to assess the results of treating
vertebral body compression fractures in osteoporotic
patients by means of percutaneous injection of
polymethylmethacrylate.
METHODS
Fifty-seven patients aged 60-89 years, 8 males and 49
females, were treated from January 2001 to July 2004. A
total of 118 fractured vertebral bodies were treated, 62
lumbar and 56 thoracic vertebrae, most of them located
close to the thoracolumbar transition. (Table 2)
After clinical assessment and magnetic resonance
imaging (MRI) study, the patients were submitted to
279
vertebroplasty under high-resolution fluoroscopic
guidance and ensuring maximum asepsis. Thoracic
vertebroplasties were performed with patients in prone
position, whereas in lumbar procedures, patients were
in lateral decubitus or prone position. For unilateral
or bilateral transpedicular approach of the vertebral
body we used 13G to 18G needles. The mean volume
of PMMA mixed with to barium sulfate was 2-3 ml per
vertebral body; it was injected at several levels, taking
care for PMMA not reaching the posterior wall.
Phlebography is performed before injecting acrylic
cement to determine localization and venous drainage.
Patients were treated under mild sedation, local
anesthesia and prophylactic antibiotic therapy. After
injection, they remained in decubitus for 20 minutes
for safety reasons. Figures 1 and 2 show the results of
PMMA injection.
RESULTS
No patient in our series developed neurological deficit
simultaneously with or after PMMA injection. One
patient presented another fracture of the vertebral
body six months after a vertebroplasty performed with
a 13-G-needle by unilateral transpedicular approach.
The patient was submitted to another procedure with
resolution of pain.
Immediate clinical improvement was observed in 54
patients (112 vertebrae), and three patients (6 vertebrae)
returned for another vertebroplasty in close vertebral
bodies. One patient had mild transient respiratory
failure probably due to migration of material (microembolism?) but had no sequela. Fifty-four patients
presented total resolution of pain in the follow-up.
DISCUSSION
Approximately 95% of patients had significant
improvement of pain and strengthening of the vertebral
body. All individuals recovered mobility due to pain relief.
The literature reports only 1% of complications, and the
most often observed are radicular pain by nerve root
compression, discitis, osteomyelitis, spinal infection,
spinal compression and pulmonary embolism(6-9).
Several retrospective and prospective studies tried
to explain improvement in painful symptoms(10-11). The
possible mechanisms involved in relief of pain include
Table 2 - Number of patients and sex distribution. Number of treated vertebrae and causes of fractures
Patients
Female
Male
Total
number of
vertebrae
Lumbar
vertebrae
Thoracic
vertebrae
Fractures
Osteoporosis
Fractures
Tumor
Improvement
57
49
8
118
62
56
85%
15%
95%
einstein. 2004; 2(4):278-81
280
Neto PP, Kihara EN, Fontoura EAF, Andrioli MS, Andrade Junior A, Romaldini H, Nóbrega JL
Figure 1. Results of PMMA injection.
Figure 2. Results of PMMA injection.
thermal and chemical reactions and mechanical factors,
such as stabilization after acrylic cement injection(12-13).
Exothermal polymerization reaction releasing heat
occurs in the transition from paste form to solid state,
in solidification of PMMA. This heat release may be
the cause of pain relief(10), but recent studies do not
support this theory due to the small amount of PMMA
used(14).
The chemical reaction by the presence of
methylmetacrylate cannot be proved until concentration
measurements of this material be performed in vivo(12).
Mechanical stability after PMMA injection reduces
movement and nerve stimuli of pain receptors located
in the periosteum, and may be the major cause of pain
relief.
Today we standardize the procedure according to
the level involved. For thoracic vertebra, we
systematically perform bilateral transpedicular
approach, whereas for lumbar fractures, we
preferentially use a posterior-lateral approach, with
intravertebral injection and pedicular approach. In some
cases we observed failures related to re-fractures are
more likely in the area with acrylic cement. In our
opinion this is due to insufficient injection of material
(0.5-1.0 ml), and it is necessary to inject PMMA again
in the areas adjacent to that already stable (2.0-4.0 ml).
It is possible to simultaneously inject PMMA in several
vertebral bodies by means of unilateral or bilateral
transpedicular approach.
Currently, vertebroplasty may also be used for spinal
bone lesions secondary to primary or metastatic
tumors(15-16). The literature reports vertebroplasty is
indicated to treat vertebrae with hemangioma in the
vertebral body(5). There are rare complications (1%)(17).
einstein. 2004; 2(4):278-81
CONCLUSION
Patients with osteoporosis and pain intensity 3,
according to McGill Melzack scale, as well as restricted
movements due to vertebral compression fracture could
be treated by means of percutaneous vertebroplasty,
with acrylic cement injected under high-resolution
fluoroscopy guidance, maximum asepsis and sedation.
Percutaneous vertebroplasty is an efficient
procedure to treat disabling pain that is secondary to
fractures related to osteoporosis and primary or
secondary/metastatic tumors.
Improved painful symptoms initiate after injection
of acrylic cement by strengthening the structure and
stabilizing the vertebral body, thus recovering its
functionality.
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