Chapter 66 Osteoporosis, Vertebroplasty, and Kyphoplasty Flashcards Preview

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Flashcards in Chapter 66 Osteoporosis, Vertebroplasty, and Kyphoplasty Deck (103):

compression fractures (VCFs) are caused by

the inability of the vertebra to sustain internal stresses applied from normal daily load or trauma. The inability of the vertebra to maintain
its structure is related to the constant change in its composition.


The primary structure of bone is distinguished

cortical, or compact bone, and trabecular bone,
otherwise known as cancellous and spongy bone.


Cortical bone is generally on

the surface and is characterized by its
dense composition without cavities


trabecular bone has many

interconnecting cavities consisting of red
blood cells and yellow bone marrow composed of fat cells


Trabecular bone

found in large supply in vertebral bodies, is largely responsible for the majority of the axial forces and
inherited extra-axial stress and strains. The extent of the two types of bone varies depending on its location.


Bone is also composed of

osteoprogenitor cells, osteoblasts, osteoclasts,
osteocytes, neurovascular progenitor cells of external origin, and an array of inorganic and organic constituents.


In multiple myeloma, there is an imbalance of

osteoclasts and osteoblasts (increased osteoclastic
activity) that can cause lytic lesions in the absence of


The majority of vertebral compression fractures are
caused by

osteoporosis, but other causes include multiple
myeloma, metastatic tumor, and hemangiomas


Decrease in
height and vertebral deformities are indications of

vertebral fractures. Most VCFs are asymptomatic, and there is no associated origin of injury


Management of vertebral deformities

Most fractures will heal
within a few months, but some have pain and disability that fail to respond to conservative therapy. Conservative therapy includes the use of back bracing, bed rest, and
pain control with medications such as nonsteroidal antiinflammatory drugs (NSAIDs), calcitonin, and narcotics.


adverse consequences of conservative therapy

deep venous
thrombosis, pulmonary embolism, pneumonia, and accelerated
bone loss can occur with prolonged bed rest.


consequences of vertebral compression fractures

height loss and kyphosis.


Initial treatments for painful compression fractures that
failed conservative therapies

usually revolved around


technique for the treatment of osteoporotic compression fractures

Percutaneous vertebroplasty. injecting polymethylmethacrylate (PMMA) into the painful vertebral body provided significant pain relief


Kyphoplasty to address
the additional consequences with vertebral compression
fractures that came along with pain (height loss and kyphosis).

the addition of inserting and inflating a balloon in the vertebral body prior to cement to restore height and decrease kyphosis



marked by a reduction in bone mass per unit volume with normal bone chemical composition, decreased skeletal function, progressive spinal deformity, and vulnerability to fractures.


Osteoporosis aka

lso dubbed “porous bone
disease” or “brittle bone disease,” osteoporosis is a universal disease



a connective tissue that is responsible for hematopoiesis, mechanical and structural support, and mineral storage of inorganic salts and organic material. Bone is constantly broken down and architecturally rebuilt to provide optimal mechanical support for its various functions.


If bone turnover, the breakdown and formation of new bone, is unbalanced,

then progression of bone loss develops.


hallmarks of osteoporosis

an increase in bone
resorption and a decrease in new bone formation.


Characteristics of osteoporosis

l It affects more women than men, as women possess 10% to 25% less total bone mass at maturity.
l Caucasian and Asian women are at highest risk of developing an osteoporotic fracture due to low bone mineral density.
l In the US, 35% of women over age 65 years and 15% of Caucasian postmenopausal women are osteoporotic.
l In the U.S, this debilitating disease causes fractures in 1 million individuals per year with $14 billion spent for treatment.
l Hip and vertebral fractures occur in women at a rate of 250,000 and 500,000 cases annually, respectively,
and an additional 250,000 fractures are experienced
by men every year.16,17
l Vertebral fractures in women increase as menopause approaches and old age, with a ratio of 2:1 compared to men.


Iatrogenic osteoporosis is
caused by

prolonged corticosteroid administration, furosemide,
thyroid supplements that suppress TSH production,
anticonvulstants, heparin, lithium (by causing hyperparathyroidism),
and cytotoxic agents.


Type I of Osteoporosis

Primarily trabecular bone
6:1 female to male ages 51–65
No calcium deficiency
Estrogen deficiency
Vertebral and Colles’ fractures prevalent
Risk factors: low calcium intake, low weight-bearing regimen, cigarette smoking, and excessive
alcohol consumption


Type II of Osteoporosis

Primarily cortical bone
2:1 females to males of age> 75 years
Calcium deficiency, decreased vitamin D, and increased PTH activity
No estrogen deficiency
Pelvic, hip, proximal tibia, and proximal humerus prevalent
Related to low calcium intake


Secondary Causes of Osteoporosis

Paget’s disease
Malabsorption syndrome
Multiple myeloma
Prolonged drug therapy
Osteomalacia hypogonadism



l Medical evaluation requires thorough investigation of family and medical history as well as physical and gynecologic
l A complete blood cell count, serum chemistry group, and a urinalysis including a pH count should be carried out.
l Consider thyrotropin, a 24-hour urinary calcium excretion, erythrocyte sedimentation rate, parathyroid hormone and 25-hydroxyvitamin D concentrations,
dexamethasone suppression, acid–base studies, serum or urine protein electrophoresis, bone biopsy and/or
bone marrow examination, and an undecalcified iliac
bone biopsy if suspected as the underlying cause.
l Dual-energy x-ray absorptiometry (DXA) to evaluate bone mineral density. Plain radiographs are an option, but changes are usually seen after 30% loss of bone mass.


following categories receive routing screening by DXA

l All women 65 years and older
l Any adult with a history of fracture not caused by severe
l Younger postmenopausal women with clinical risk
factors for fracture


diagnostic criteria to designate the presence of
osteoporosis based on DXA measurements

Normal individuals possess a bone mineral density of one standard deviation (SD) of the mean of young adults. If bone mineral density is measured
2.5 or more SDs below the mean of a young adult population, then osteoporosis is present.



indicated if the SD of bone mineral density is between 1.0 and 2.5 below the mean of a young adult population.


severe osteoporosis is denoted when

one or more accompanying
fragility fractures is present.


Bone Mass Density in women

Women lose 3% to 7% of BMD around the onset of menopause followed by a 1% to 2% decline yearly in the postmenopausal period


appropriate regimen of preventive
and therapeutic measures to combat osteoporosis

l Calcium and vitamin D
l Bisphosphonates
l Calcitonin
l Selective estrogen receptor modulators
l Parathyroid hormone
l Sodium fluoride
l Exercise
l Modifiable risk factors such as cigarette smoking, excessive alcohol consumption, and treatment of potential secondary causes


Osteoporotic fractures are more prone to occur at the

hip, ribs, wrists, and vertebrae.


contribute to the complications of an
osteoporotic hip fracture.

pneumonia, blood clots in the lungs, and heart failure


Vertebral compression fractures (VCFs) can decrease height by up to

15 cm and result in the
kyphotic deformity called “dowager’s hump.”


Vertebral compression fractures occur due to the

inability of the osteoporotic vertebra to sustain internal stresses applied by the vertebral load from daily life or from minor or major traumatic events.


Trabecular bone

largely responsible
for the majority of the axial forces and inherited
extra-axial stress and strains. With the cascade of osteoporotic effects and aging, the architecture of trabecular bone becomes altered, characterized with increased spaces, thinness,
disorientation, and weakened connectivity


compromise the vertebra’s mechanical prowess, integrity, and spinal column stability, predisposing
it to trabecular buckling

a decrease in density and loss of structural strength


Multiple VCFs develop a

hyperkyphotic or “dowager’s hump” at the thoracic level with a stooped posture decreasing
abdominal and thoracic cavities. Multiple lumbar VCFs further increase lordosis, creating a protruding abdomen.


A decrease in axial height is a result of reduction of

intervertebral and vertebral loss of height. Also, developed stooped
posture progresses to the point where ribs rest on the iliac crest with circumferential pachydermal skin folds developing at the pelvis and ribs.


The cauda equina or spinal cord related symptoms
are uncommon and are secondary to other conditions, such as

Paget’s disease, lymphoma, primary or metastatic
bone tumors, myeloma, and infection


Effects of VCF on life

When awakening, the abdomen appears normal, only to distend throughout
the day. Nonrestorative sleep or trouble getting to sleep is often the case with patients. Lifestyle changes occur, such as difficulty driving a car, getting dressed, fear of large crowds, and depression. Self-esteem is also compromised as a result
of a socially unacceptable body image.


the most common primary malignant tumors of the bony spine that rarely affect the posterior elements.

Multiple myelomas


Diffuse multiple
myeloma presents

reoccurring lesions at previously radiated levels and offers a poor prognosis


Management of multiple

Initially, patients
report severe pain and disability and are unresponsive to drug treatment. The disease is usually multifocal in nature and surgical consolidation is not advantageous. In spite of this, single-level lesions are treated with vertebrectomy and strut grafting with some success. radiation therapy alone or as an adjunct to surgery to address the painful manifestation of malignant lesion offers partial or
complete pain relief.


Vertebral augmentation for Multiple Myeloma

Vertebral augmentation offers an alternative route for immediate pain relief, bone strengthening,
and mobility. Although vertebral augmentation goes some way to restoring the mechanical integrity of the vertebral
body and provides a degree of pain relief, tumor growth is not prevented. Therefore radiotherapy accompanying
augmentation is appropriate because it does not affect the
properties of the bone cement, affects tumor growth, complements
pain relief, and effects spine strengthening



benign bony spine lesions. Often, hemangiomas are detected during evaluation of back pain and subsequent routine plain radiographs. Soft tissue
extension of the lesion may compress the spinal cord and nerve roots producing neurologic symptoms and even produce epidural hemorrhage.


If extensive growth of the
hemangioma transpires,

vertebral integrity may be compensated, resulting in fracture with associated pain at the level of the lesion.


signs of the aggressive nature of hemangiomas and their candidacy for vertebral augmentation

Vertebral collapse, neural arch invasion, and soft tissue mass extensions


metastatic tumor
develop malignant lesions in the spine common location

thoracic spine but all levels can be affected and usually more than one level is involved


The most important aspect of patient evaluation of VCF begins with

good clinical history and physical exam


Patients with symptomatic VCF typically present with

acute or subacute back pain with no associated major trauma or precipitating event. The sudden onset of pain is
usually described as a moderate to severe, deep ache, at midline location, and exacerbated by any motion. More specifically, pain is experienced when standing from a seated position, bending, lifting, and prolonged sitting
and/or standing. Walk is sluggish, but gait is normal.
Coughing, sneezing, and bowel exertion exacerbate pain.


Pain of VCF may be relieved by

recumbent positioning and bed rest


In VCF Physical examination will usually find a patient in

mild to severe distress depending on the the general conditioning
of the patient as well as the location and type of fracture. There is usually tenderness at the site of fracture in the midline, but its absence does not rule out the presence
of an unhealed fracture.



may also be an important
indicator of VCF as loss of more than 4 cm of height
is associated with 15 degrees of kyphosis


imperative to rule out other causes of symptoms, especially myelopathy,
radiculopathy, and spinal stenosis

musculoskeletal and neurological exam


Diagnosis of VCF

Decrease in height and vertebral deformities are indications of vertebral fractures. VCFs maintain an axis of rotation at the middle column. As a
result, anterior column disruption is seen with intact middle and posterior columns.


Bioconcave VCFs manifest as a

central vertebral deformity
as a crush fracture involves anterior, posterior, and central aspects.


Wedge fractures

the most common VCFs, affecting anterior elements more often than posterior.


VCFs adopt, fractures
occur more often at the

thoracolumbar and midthoracic region


Once there is suspicion of VCF or new-onset, moderate to severe back pain not explained by any other cause

radiographic imaging should be ordered. The simplest, most cost-effective initial study is a plain AP and lateral x-ray of the suspected area of the spine. However, if there
is a high clinical index of suspicion, it is reasonable to proceed straight to magetic resonance imaging (MRI).


MRI is useful in determining

acute versus chronic fractures (edema on T2 weighted image) as well as determining any canal compromise or tumor presence. A hypointense T1 weighted image is also suggestive of edema


Short tau inversion recovery (STIR)

a type of MRI that is used to suppress the hyperintensive image readings of
substances such as fatty tissue and cerebrospinal fluid. STIR is the most sensitive imaging sequence for visualizing edema, and edema is highly predictive of success with vertebral augmentation


If MRI is contraindicated, then either

bone scan or computed
tomography (CT) scan may be useful in determining
the acuity of the fracture. Acute or unhealed fractures will take up the injected 99mTc-MDP tracer in higher concentrations on bone scan. Thin-section (< 3 mm) CT is often used in conjunction with MRI reconstructions in
order to derive the most accurate visualization of the target vertebral levels.


CT has been cited specifically as the best modality for

determining whether or not a fracture line has extended through the posterior wall of a vertebral body. CT can also see fracture cavities that should be the targets.


Comprehensive evaluation of the patient should also
include other causes of VCFs

Complete blood count
Serum calcium
Serum alkaline phosphatase
Serum creatinine
Urinary calcium excretion
Serum 25-hydroxyvitaminD
Serum protein electrophoresis
Sex steroids
Serum aminotransferase
Serum TSH


Once a determination is made that VCF is the cause of the patient’s pain, steps should be taken to

manage and keep the patient weight bearing and prevent functional


Management of VCF

Initial modalities include walking aids and lumbar supports, but efficacy of
lumbar supports has limited evidence and my cause more harm if used chronically.


Exercise programs have demonstrated

decreased use of analgesics, improved quality of life and increased bone mineral density along with evidence that 1% of bone loss per year in the spine and hip is prevented or reversed.


Pharmacologic therapy for VCF

NSAIDs if tolerated, short- or long-acting opioids, and, possibly, calcitonin.


Acute pain from VCF can persist up to

12 weeks, while chronic pain is secondary to vertebral deformity, paraspinal muscle spasm, or degenerative arthritis in the region of the fracture.


At any time point, if
pain is uncontrolled to the extent that the patient cannot perform weight-bearing activities, or has side effects from analgesics

vertebral augmentation should be considered,
assuming that proper workup is completed and the VCF is the source of pain


requirements for the procedure include:

l IV access and sedation; possibly general anesthesia.
l Image guidance—usually fluoroscopy, possibly computed tomography or both. Some practitioners advocate using a biplanar fluoroscope to always have an AP and lateral image. This is convenient and saves time, but is not necessary.
l Informed consent.
l IV antibiotic prophylaxis—cefazolin 1 g or clindamycin 600 mg—within 60 min of incision.
l Appropriately padded table for prone positioning.
l Sterile precautions.
l Appropriate bone biopsy needles with opacified PMMA.



There are two different techniques in placing the
11- or 13-gauge needles

transpedicular and parapedicular. In general, the augmentation of the lumbar and lower thoracic (below T10) spine is usually performed with a transpedicular approach,
while the upper thoracic spine (above T8) is done with either route, but usually parapedicular




Intravenous antibiotics should be given within 60 min of incision. Once the patient is in position and pressure
points are padded, the C-arm is brought in to identify the proper level or levels to be augmented. This level is marked and the area is prepped and draped in usual sterile



For the transpedicular approach, there are two methods that can be utilized and can be simply defined as

the AP approach (maintaining visualization of the medial and lateral cortex of the pedicle) versus the en face approach (tunnel vision). Regardless of approach, an AP image is first obtained of the appropriate level.



If utilizing the en face approach

the C-arm is then angulated ipsilateral oblique to place the pedicle in the middle of the vertebral body



For the AP approach, the target needle site is the

and lateral portion of the pedicle, sometimes described as the 10 o’clock or 2 o’clock for the left and right pedicle on AP view, respectively. If utilizing the oblique view, then
the needle should be placed in the center of the pedicle




Local anesthetic is infiltrated intradermally and subcutaneously. A 22-gauge spinal needle is then advanced coaxially to the periosteum of the pedicle. Then 5 to 10 ml
of either 2% lidocaine or 0.5% marcaine is injected at the periosteum and during withdrawal of the spinal needle to anesthetize the tract of the larger needle. Then, a small incision is made with an 11-blade scalpel. The needle is
advanced to the pedicle in the tract of the spinal needle. After the needle is engaged into bone, either a screwdriver
technique or gentle tapping with an orthopedic hammer is used to drive the needle into the pedicle with frequent imaging to confirm that the needle is within the pedicle




Once needle is properly engaged

an AP view is obtained to confirm that the medial cortex of the pedicle is not violated. A lateral image is then obtained to confirm that the needle is within the pedicle
and not cephalad or caudal, in which case a disc or nerve
foramen may be entered




For vertebroplasty, the needle is advanced into the

anterior third of the vertebral body, while for kyphoplasty the needle is only advanced
into the posterior third




The parapedicular approach involves

placing the needle
lateral to the edge of the pedicle and advancing along
the surface of the pedicle directly into the vertebral body.
Initial needle placement is lateral to the lateral cortex of
the pedicle. The vertebral body is entered the junction
of the pedicle which will appear more anterior on lateral
imaging. More medial placement of the needle in the vertebral body, and thus greater likelihood of a single needle placement, may occur with this approach. This approach may be preferred for treatment of compression fractures above T10 because
of the smaller pedicle size.


The goal of augmentation
is to

have filling of all of the fracture lines.



initial needle placement

similar to
the vertebroplasty approach except that the needle is not
advanced past the posterior one-third of the vertebral body. Also, the introducer system is slightly larger than the vertebroplasty needles.




The introducer has a beveled or diamond tip, which allows it to be gently hammered or manually pushed into the vertebral body. After entering the posterior aspect of the vertebral body, the introducer is removed
leaving the cannula in place. A hand-operated drill is advanced to the anterior aspect of the vertebral body taking care not to violate the anterior margin on lateral imaging.




Ideal placement on AP imaging is in the midline. The drill is then removed and the deflated balloon is advanced through the cannula into the cavity. created by the drill. A second introducer and balloon should be placed on the opposite side in a similar fashion. Each balloon is attached to a locking syringe that has a
digital manometer followed by slow inflation with iodinated
contrast. Both manometry and fluoroscopy are used
to monitor balloon inflation



inflating the balloon until:

l Maximum pressure (up to 400 psi) or volume is reached.
l The balloon tamp reaches any cortical margin.
l Correction of the kyphotic deformity.
l The balloon is then deflated and removed.



the PMMA contains a sterile barium sulfate powder to provide radiographic opacity. There are various PMMA mixing and delivery
options for both vertebroplasty and kyphoplasty


For vertebroplasty

a cannula from the cement mixer is
connected to the needle and the cement is slowly injected
under live fluoroscopy in the lateral position. Injection is stopped periodically with intermittent fluoroscopy during
“rest” periods to ensure proper control of cement spread
and avoid aberrant placement.



Injection is stopped when the

posterior one-third or one-fourth or any other cortical margin is reached



The stylet must be
placed into the needle to

complete the injection and not allow the cement in the lumen of the needle to track
back in the needle which could cause cement leakage into
neural foramen, spinal canal, or paraspinal muscles. The stylet is placed under live or intermittent fluoroscopy to visualize final spread of cement.



For kyphoplasty

the cement has a slightly greater viscosity than the one used during vertebroplasty. PMMA is injected using a blunt cannula under live fluoroscopy. Injection is stopped
when the cavities are filled along with any potential fracture
line outside of the cavity.



After the cement is injected, the delivery system

removed and pressure is maintained on the incision sites.


Contraindications to Vertebral Augmentation


Uncorrectable coagulation
Allergy to PMMA or contrast
Spinal instability
Active site infection or sepsis
Fractured pedicles
Burst fractures
Young age
Pain unrelated to fracture
Solid tissue or osteoblastic


Contraindications to Vertebral Augmentation


Inability to lie prone
Loss of vertebral height 66%
Posterior wall destruction
20% retropulsion with spinal
Previous spinal stenosis
Vertebra plana
Multiple previous surgeries
Poor pulmonary status
Greater than three compression


complications of Vertebral Augmentation

l Osteomyelitis
l Hematoma (paraspinal or epidural)
l Rib fracture
l Sternum fracture
l Adjacent vertebral fracture
l Pedicle fracture
l Pulmonary embolus of PMMA
l Hypotension
l Cord compression
l Epidural abscess
l Neurologic complications
l Allergic reaction to contrast or PMMA


if there is any postprocedural neurologic compromise
caused by bleeding or cement leakage into the epidural
or foraminal space

Surgical decompression


Adjacent vertebral fractures are a significant concern with
vertebral augmentation

A vertebral compression fracture
causes a focal kyphotic deformity that moves the center of
gravity forward, which increases the load onto adjacent


Vertebroplasty Advantages

Lower cost
Shorter procedure
Decreases pain
Infrequent clinical sequelae due to cement extravasation
Often done under local anesthesia
Stabilize and strengthen vertebral body



42% cement extravasation
Limited correction of lost vertebral Body height
Cannot correct sagittal imbalance


Kyphoplasty Advantages

Lower cement extravasation
Lower complication rate
Equivalent pain relief
Vertebral body height restoration
Sagittal imbalance correction
Stabilize and strengthen vertebral body


Kyphoplasty Disadvantages

Increased cost
Increased procedural time More likely to require general anesthesia
Usually requires overnight hospital stay


Kyphoplasty has been touted to restore

vertebral body
height and restore sagittal alignment.

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