Microsoft word - vertebroplasty.doc

The 2nd ASEAN-AAOS Instructional Course
and the Combined Meeting of
the 24th AOA Annual Meeting and
the 26th Annual Meeting of RCOST
(2nd ASEAN-AAOS / 24th AOA / 26th RCOST)
for The Celebrations on the Auspicious Occasion of
Her Majesty the Queen’s 6th Cycle Birthday Anniversary 12th August 2004
Book of Abstract
October 13-17, 2004
Pattaya Exhibition and Convention Hall (PEACH)
Royal Cliff Beach Resort, Pattaya, Thailand
Vertebroplasty
Warat Tassanawipas, MD.
Osteoporotic Spine Fracture Treatment

The goal of osteoporosis treatment plan is to prevent further bone loss and fracture reduction rate. Currently, there are antiresorptive and bone forming drug that can increase bone mass but never reach to normal. Even increase bone mass a few percents but rate of fracture have been shown markly decrease. Besides the medication, as exercise program is both an excellent prevention of new fracture and treatment of the fracture. Exercise program includes spine extension and avoid flexion, abdominal strengthening, upright walking and daily gentle aerobic exercise. If has been shown that one hour of exercise 2-3 times per week can increase bone mineral content in the lumbar spine and total body calcium. Most of the currently drugs available are antiresorptive agents which are : Raloxifene (Selective Estrogen Receptor Modulator, SERM) A recent
study has demonstrated a 40% reduction in new vertebral fractures among
women who have had a previous vertebral fracture and a 60% reduction in new
vertebral fracture in women who have never had a previous fracture and the
BMD in increased by 2% Bisphosphonate.
Alendronate
has been shown 50% reduction in spine and hip fractures with increase bone mass up to 10%. Alendronate is also effective for preventing osteoporosis in early postmenopausal women without osteoporosis at baseline. Four year study of alendronate increase spine and hip BMD ; relative to placebo , and significantly reduced the rate of bone loss at the forearm and total body. Biochemical markers of bone turnover were reduced by ad much as 60% relative to baseline. Discontinuation after 2 years of Alendronate treatment led to rates of bone loss similar to rates in the placebo group and moderate increase in biochemical markers of bone turnover. Risedronate can also decrease fracture rate up to 30% of the new vertebral
The findings of third generation bisphosphonates such as lbandronate and Zolendronate can be of help in making this therapy more acceptable to the
patient, for example administration of lower oral doses and thus less toxicity at
the acceptable alternative administration routes such as transdermal patch.
Calcitonin
Calcitonin has been shown to increase bone mass about 3% and Parathyroid Hormone: Neer reported that daily injections of Parathyroid
hormone ( 1-34 ) at a dose of 20 microgram and 40 microgram increased the bone mineral density of the spine by 9 and 13 percentage points more than did placebo, and reduced the risk of new vertebral fractures by 65 and 69 percent respectively as compared with placebo, Daily treatment with parathyroid hormone ( 1-34 ) reduced the risk of nonvertebral fracture by 35 percent at the 20 microgram dose and by 40 microgram dose and reduced the risk of nonvertebral fragility fractures by 53 and 54 percent respectively. Dietary supplementation of both calcium and vitamin D is necessary in
patients especially the elderly. The recommendation for daily intake of calcium is
1.5 gram and 800 units of vitamin D.
A
for the lumber spine or a hyperextension brace for the thoracic spine is recommended for pain control but unlikely to prefer further collapse or
new fractures. However early mobilization and ambulation are encouraged with
physical therapy
Surgical Intervention
Vertebroplasty
was first used in 1984 by Deramond to treat a hemangioma(1,2). Early reports focused on these as well as metastatic and myelomatous lesions. Later reports included and focused on patients with osteoporosis as well(3-7). Though minimally invasive, this procedure can be deceptively intricate and dangerous if proper technique is not used. The most common complication is from migration of cement PMMA, resulting from improper needle placement, the inability of the pathological vertebral body to contain the cement. or poor injection technique. Migration of into the spinal canal can compress the spinal cord and /or nerve roots with severe consequences of neurological deficits. Biomechanical studies on cadavers show that vertebral body strength is
immediately improved by PMMA(8). These results did not vary with single or
bilateral injection. They also suggest that the strengthening of the vertebral body
is independent of the amount of PMMA used(9-11) Outcomes in terms of pain
relief may be independent of volumes injected but vary with diagnosis(4)
Radiological
evaluation
should include lateral plain X – rays and a compute tomography (CT) or magnetic resonance imaging scan. A magnetic resonance image provides the most information. Epidural disease and canal compromise will also be revealed. Bone scans will also identify acute or active vertebral processes Indication The principal indication for vertebroplasty is pain. Patients who
are most likely to benefit are those with pain localized to and osteoporotic or
osteolytic vertebral compression fracture. These fractures may be the result of
primary osteoporosis, secondary osteoporosis (e.g., chronic steroid use), or a
neoplastic process (e.g., multiple myeloma, metastatic disease). The physical
examination should correlate with the radiological evaluation.
Contraindication: Contraindications to vertebroplasty include coagulo-
pathies,infection, pregnancy, vertebra plana and spinal cord or nerve root
compression from retropulsed bone or epidural neoplastic disease, and pain
unrelated to compression fracture. Relative contraindications include vertebral
bodies collapsed greater than 75% , posterior vertebral wall destruction, and level
above T6. The smaller targets are more difficult to cannulate accurately, and the
risk of neurologic damage from needle placement or PMMA migration increases.
Complication: including death, bleeding, major vascular injury, infection,
pneumothorax, hemothorax. permanent neurologic injury, paralysis, pulmonary
embolus of PMMA,
Positioning : Although vertebroplasty can be performed with the patient
positioned in the lateral decubitus position, prone is technically more
advantageous for the surgeon, Preoperative knowledge of a patient is ability to
tolerate the prone position is useful.
Technique: The patient is placed in the prone position on a radiolucent table for
both the lumbar and thoracic levels. The patient is arms are positioned in
extension. One positioned, a mobile C – arm fluoroscope is positioned to identify
the pathologic levels and to ensure there is no obstruction to posterior – anterior
and lateral imaging.
After satisfactory fluoroscopic evaluation, the patient is prepped and draped in
the standard surgical fashion. Preoperative intravenous antibiotics are given. The
desired entry point is chosen. Both transpedicular approaches can be used. The
transpedicular approach is safer in the lumbar spine because of the larger size of
the pedicles. X – ray irradiation is turned off, the skin and subcutaneous tissues
are anesthetized with local Lidocaine followed by a stab incision with number 11
blade. The trochar is aligned advanced to the target. When cortical bone is
encountered, the trochar is tapped with a mallet to engage the bone, and a
confirmatory fluoroscopic image is obtained, the C – arm is rotated to the lateral
position, and the trochar is advanced into the anterior third of the vertebral body
under direct visualization. Ideally, this should be properly placed on the first
pass, because with each failed attempt a new exit hole is created for potential
PMMA migration. For the extrapedicular approach, the trochar is passed through
a portion of the transverse process or rib.
A venogram is performed to ensure that is no direct communication with the inferior vena cava or epidural veins. After satisfactory needle placement, the PMMA is prepared. Surgical Simplex P (How medical International 40 g of sterile powder including 6 g of PMMA) was employed. One half of the powder is used with 3 additional g of barium sulfate added for adequate fluoroscopic visualization during delivery. Approximately 75% of the catalyst is added to the PMMA powder and barium mixture and stirred until a viscous compound is achieved. Tuberculin syringes filled about half way are used to inject the PMMA. Complications are directly proportional to the volume delivered. Controlled PMMA delivery is best performed under low pressure and direct fluoroscopic visualization. The sty let of the trochar or needle can be used to “ plunge ” the thick PMMA down the needle shaft. If there is any question of PMMA leakage into large draining veins or the epidural space, the procedure is aborted. If sufficient PMMA has crossed the midline, a bilateral procedure is avoided. A neurologic examination should be performed in recovery or when the patient wakes up from anesthesia. A postoperative CT scan should be obtained for self – assessment. Patients can be treated in an ambulatory setting if their overall health permits and provided the facility is prepared to handle an emergent open spinal surgical procedure in the event that this becomes necessary. Improvements have already been made and more are safe to follow in this relatively new procedure. Single side injection, direct vertebral body puncture, increasing x-ray opacification with barium sulfate, limiting volume of PMMA injected. Conspicuous areas of improvement should be forthcoming in Bioceramics. The need exists for development of materials that are easier to inject, migrate less, release less heat and potential toxins, and are more biocompatible with the surrounding bone. Roles of surgical intervention in osteoporotic spine fracture has been modified as the recently new technique called Kyphoplasty. A modification to this technique is the Balloon Vertebroplasty or Kyphoplasty, the balloon is introduced and inflated of the balloon in order to restore vertebral height and PMMA is injected. In addition to the recovery of vertebral height and the correction of a segmental kyphosis, a third advantage to the balloon technique is the relatively low pressure that is required for the injection , ad compared to the original vertebroplasty technique . these kyphoplasty was done for the pathologic and timorous vertebral fractures . Although the indications for this procedure are still not clearly defined. The compression fracture that remains recalcitrant to medical management and is associated with marked kyphosis may be and excellent candidate for this procedure.
Summary: Vertebroplasty is generally a safe and effective procedure to control
pain associated with fractures of the spinal column. Significant complications can
occur and are likely underreported. Good technique can minimize risk of PMMA
migration. The learning curve should be moderately quick and safe if physicians
familiarize themselves with these axioms.
References

1. Galibert P. Deramond H. Rosat P, Le Gars D. Note preliminaire sur letraitement des angiomes vertebraux par vertebroplastie acrylique percutanee. Neurochirurgic 1987 ; 33: 166-8. 2. Deramond H, Depriester C, Galibert P, Le Grafts D. Percutaneous vertebroplasty with polymethylmethacrylate: technique, indications, and results. Radiol Clin North Am 1998;36:533-46. 3. Barr JD.Barr MS,Lemley TJ. McCann RM. Percutaneous vertebroplasty for pain relief and spinal stabilization. Spine 2000;25:923-8. 4. Cotton A, Boutry N. Cortel, et.al. Percutaneous vertebroplasty: state of the 5. Gangi A, Kastler BA. Dietemann JL. Percutaneous vertebroplasty guided by a combination of CT and fluoroscopy. Am J Neuroradiol 1994;15:83-6. 6. Jensen ME, Evans AJ, Mathis JM, Kallmes DF, Cloft HJ, Dion JE. Percutaneous polymethymethacrylate vertebroplasty in the treatment of osteoporotic vertebral body comporession fractures:technical aspects. Am J Neuroradiol 1997;18:1897-904. 7. Weil A, Chiras J, Simon J,et.al. Spinal metases: indications for and results of percutaneous injection of acrylic surgical cement. Radiology 1996;199:21-7. 8. Cotton A, Dewatre F, Cortet B, et.al. Percutaneous vertebroplasty for osteolytic metastasis and myeloma: effects of the percentage of lesion filling and the leakage of methyl methacrylate at clinical follow – up Radiology 1996;200:525-30. 9. Dean JR, Ison KT, Gishen P, The strengthening effects of percutaneous vertebroplasty. Clin Radiol 2000;55:471-6. 10. Tohmeh AG, Mathis JM, Fenton DC, Levine AM, Belkoff SM. Biomechanical efficacy of unipedicular versus bipedicular vertebroplasty for the management of osteoporotic compression fractures. Spine 1999;24:1772-6. 11. Belkoff SM, Mathis JM, Erbe EM, Fenton DC, Biomechanical evaluation of a new bone cement for use in vertebroplasty. Spine 2000;25:1061-4. 12. Moreland DB, Landi MK, Grand, W. Vertebroplasty : techniques to avoid

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