Kyphoplasty - A Minimally Invasive Approach to the Treatment of Vertebral Compression Fractures.
Last updated Wednesday, February 09, 2005
Catheter - Once the catheter is in proper position, a balloon is inflated within the vertebral body to reestablish the proper bone height. Fracture - Vertebral compression fractures (VCF) are injuries to the spinal bones. These are equivalent to a break of the wrist bone(s), but occur through the vertebral body of a spinal bone. Bone density - Normal Bone -- Osteoporotic Bone Stabilizing the injured vertebral body - insertion of a type of bone filler (methylmethacrylate cement) into the vertebral body SummaryOverview Kyphoplasty is a minimally-invasive surgical procedure offered for
the treatment of vertebral compression fractures of the spine. These
fractures result from a variety of causes, of which, osteoporosis is
the most common. Vertebral fractures also result from primary
processes, such as, a trivial fall or other traumatic events, as well
as, from secondary conditions like multiple myeloma or after radiation
therapy for a cancer treatment. The goals of this procedure include
pain relief, providing spinal stability, correction of spinal
deformity, and improving an individual’s quality of life through
restoration of patient function. This is accomplished by placing a
catheter-like device into the broken vertebral body under radiographic
visualization.
Once the catheter is in proper position, a balloon is inflated
within the vertebral body to reestablish the proper bone height. In
doing so, a simultaneous attempt to correct the altered spinal
alignment is made. Maintenance of this corrected vertebral height and
alignment is achieved through placement of a type of bone filler, such
as, methylmethacrylate cement (bone cement). Once performed, the
fractured vertebral bone(s) have improved stability often eliminating
the need for traditional methods of treatment like wearing a brace.
Many patients, as a result, are typically able to return to normal
daily activities much sooner, have a decreased need for pain
medications, a shorter hospital stay, and improved quality of life. Characteristics of vertebral compression fractures Vertebral compression fractures (VCF) are injuries to the spinal
bones. These are equivalent to a break of the wrist bone(s), but occur
through the vertebral body of a spinal bone (See Figure).
These fractures, most commonly, result from osteoporosis or other
processes which cause osteoporosis. Osteoporosis is a condition which
results in decreased bone mineral density, and as a result, weakened
bones.
Conditions which often lead to osteoporosis include estrogen
deficiency (from menopause or premature onset of menopause), multiple
myeloma (a blood cancer which can affect the spine), radiation therapy,
and simply the natural aging process. Because a patient’s skeletal
system is weakened either due to the primary disease process or as a
result of treatment of such diseases, such an individual’s bones are
more prone to fracture. Common sites osteoporotic fracture (breaks)
include the spine, hip, and wrist.
Vertebral compression fractures involve only the anterior column of
the spine. The spine is divided into three columns for classification
of spinal fractures to help guide in the treatment of the different
fractures which can occur (See Figure).
Kyphoplasty is only recommended in the treatment of fractures of the
anterior column of the spine (VCFs). Other fracture types which affect
the spine result in a greater degree of spinal instability, more severe
spinal deformity, and a higher risk of neurologic deficit
(abnormality). Consequently, the risks associated with the utilization
of kyphoplasty in such circumstances usually outweigh the benefits of
the procedure and is therefore considered inappropriate. Types VCFs are not fractures without consequence. These spinal fractures
can result in tremendous back pain both in the short and long term.
Because the injured vertebrae is compressed or loses height, a
deformity of that particular vertebrae and the spine as a whole often
results (kyphosis). This deformity, in and of itself, can produce pain
long after the VCF, itself, has healed.
Such kyphotic deformity can lead to additional problems, such, as in
increased risk of adjacent level fractures, abnormalities of the chest
cavity which can result in shortness of breath, ambulatory impairments,
and difficulties with sleep. Other attempts at conservative,
nonoperative treatment of VCFs often are ineffective in preventing
these adverse consequences. Kyphoplasty, on the other hand, attempts to
return patients to their previous levels of function, decrease the time
of functional impairment, and prevent the detrimental long term
consequences of VCFs. This is done by stabilizing the injured vertebral
body through insertion of a type of bone filler (methylmethacrylate
cement) into the vertebral body after the bones height has been
restored through inflation of a balloon like tamp which elevates the
compressed vertebral endplates (See Figure).
VCFs are extremely common fractures. In fact, they are the most
common osteoporotic fracture to occur. Over 700,000 VCFs occur yearly.
Following the first occurrence of a VCF, there is a fivefold or five
times more likely risk of a second VCF. Many patients (approximately
260,000) do not respond favorably to medical treatment. Patients either
cannot tolerate the bracing required, or have adverse reactions to the
prescribed narcotic medication, have a prolonged period of disability,
or suffer from the adverse long term consequences of VCFs. Other
problems which can be associated with VCFs include impaired mobility,
decreased appetite, low self esteem, diminished social interaction, and
loss of independence. Impaired mobility, per se, leads to additional
bone loss and a worsening degree of osteoporosis. The decrease in
appetite can occur as a result of the spinal deformity (kyphosis) which
can leads to compression of the abdominal contents. An individual’s
independence can be affected due to all of the above mentioned
consequences of VCFs, which for the most part, result from the spinal
deformity which commonly results form such fractures. Incidence and risk factors Risk factors for such VCFs include female gender, Caucasian race, early
menopause, advanced age, radiation therapy, sedentary lifestyle,
inadequate calcium intake, hyperthyroidism, hyperparathyroidism,
corticosteroid use, many cancer therapies, organ transplantation,
alcoholism, smoking, and eastern European decent to name only a few.
Males, similarly, are at risk. The risk, however, is somewhat less
because males usually have a higher bone density to start out with and
typically are subjected to more strenuous weight-bearing activities of
daily living. But, females are becoming more and more active,
consequently, the differences in risk are becoming less apparent. Other
medications besides corticosteroids (Prednisone) accelerate
osteoporosis (Dilantin). Effective therapies to prevent osteoporosis
include regular aerobic exercise, calcium supplementation (with Vitamin
D), hormonal replacement therapies, activity modification, and
bisphosphonate medical therapy.Who should consider kyphoplasty? The diagnosis of VCFs is generally suspected in patients over 65 years
of age who suffer develop acute complaints of back pain. Often only
trivial traumatic episodes are involved. There may or may not be
tenderness over that particular area of the spine or minimal tenderness
with an increasingly progressive curve to the spine. Plain X-rays
typically demonstrate the fracture by presence of a fracture line, loss
of bone height, and possibly a kyphotic deformity. Rarely, is
additional imaging required for the acute diagnosis. Often, however, a
CT Scan of MRI is required to eliminate the possibility of a pathologic
fracture (tumor or infection) and to properly classify to fracture.What happens without surgery? Kyphoplasty is not recommended for all VCFs. Some fractures have
minimal associated deformity or pain and are usually stable fractures.
In this case, no treatment is required other than a short period of
activity modification. If, however, a painful VCF is diagnosed and
fails to improve with nonoperative treatment within about two weeks,
then, such individuals may be candidates for the kyphoplasty procedure.
In addition, if the traditional VCF treatments are not successful in
managing the associated pain of if deformity develops, kyphoplasty can
be considered. Preoperative assessment usually includes a series of
plain X-rays, a CT scan (to make sure the injury is a compression
fracture), and MRI scan, and possibly a Bone Scan. Consequently,
referral for kyphoplasty can be initiated through the emergency room
physician, primary care physician, or even in some cases by the patient.Surgical options Previous treatment options for management of VCFs include bedrest,
brace wear, analgesic medication, narcotic medications, and activity
modification. All of these options have met with some degree of success
and failure. For the most part these methods have been unsuccessful or
required prolonged period of immobility and functional restriction.
Surgical treatment of VCFs previously included utilization of rod and
screw type instrumentation to stabilize the injured vertebrae and
correct deformity through spinal fusion. This type of procedure is
quite extensive for the treatment of such fractures and, fortunately,
rarely required. Such a fusion procedure is recommended only in cases
where there is associated neurologic deficit (abnormality), adjacent
level fracture, severe deformity or spinal instability, or pathologic
fracture (tumor/infection). Another surgical procedure called
Vertebroplasty has been offered to patients for treatment of VCFs. It,
similarly, attempts to stabilize the fractured vertebrae through the
utilization of methylmethacrylate cement (bone cement), but makes no
attempt at correction of spinal deformity. Therefore, it has met with
limited success and patient satisfaction.Technical details Kyphoplasty is performed in the operating room usually under a general
anesthetic. The procedure requires a patient to be positioned prone
(face down) on the operating table and fluoroscopic imaging is utilized
by the surgeon to carefully monitor the procedure. The complication
rare low, but this is not to state that there are no complications. The
most feared complication related to kyphoplasty is creating a
neurologic deficit. This may occur through an extravasation of the bone
cement into the spinal canal (cement leak). Such a cement leak may
occur through the low resistance veins of the vertebral body or through
a crack in the bone which has not been appreciated previously.
Fortunately, this type of occurrence is very rare. Other complications
include; additional adjacent level vertebral fractures, infection,
cement embolization, and death. Adjacent level fractures are not
actually a direct result of the procedure, but may occur because the
stabilized vertebrae are much stronger and the adjacent vertebral
levels may remain in a weakened state. These adjacent levels,
frequently, may also be treated with kyphoplasty. Cement embolization,
on the other hand, occurs by a similar mechanism to a cement leak. The
cement may be forced into the low resistance venous system and travel
to the lungs or brain resulting in a pulmonary embolism or stroke. The
incidence of such devastating complication is, as stated earlier on,
very low.Summary of kyphoplasty for vertebral compression fractures Consequently, the risks of kyphoplasty are few, but the benefits vast.
The procedure is typically performed after a same day hospital
admission and requires a 24 hour hospital stay. Only two small
incisions to the right and left of the midline are required. The damage
caused to the muscle, ligaments, and other spinal structures is
minimal, resulting in less post-operative pain, a decreased need for
pain medication, and faster recovery. It is also presently covered
under Medicare benefits.
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