Jon K. Kostelic, M.D.
Osteoporotic compression fractures represent a significant
source of disability in the elderly population. Approximately 700,000
vertebral body fractures occur annually in the United States. The
lifetime risk of a symptomatic vertebral fracture for women is 16%.
The high incidence and prevalence of these fractures result in significant
cost. The annual cost related to osteoporosis is approximately $10
billion per year in the United States. For vertebral osteoporosis
alone, there is a direct identifiable cost of over $600 million.
In addition, there is significant morbidity associated with these
Of clinically detected fractures, 84% are associated with pain.
The pain typically lasts 4 to 6 weeks, with greater degrees of deformity
resulting in a greater likelihood of pain or disability. This pain
may also result in reduced exercise tolerance, weight loss, difficulty
with self-care, depression, and sleep disorders. Furthermore, the
likelihood of developing life-threatening deep venous thrombosis
or pneumonia is accelerated in those individuals with symptomatic
vertebral compression fractures. Current therapy involves symptomatic
relief with analgesics, immobilization, external bracing, and, rarely,
surgery. Preventative measures such as hormone replacement therapy
and calcitonin are also used. Clearly, osteoporotic compression
fractures represent a significant source of morbidity and mortality
in the elderly population.
Percutaneous vertebroplasty offers an option for treatment of acutely
symptomatic or refractory osteoporotic compression fractures. The
procedure involves placing an 11-gauge trocar into the affected
vertebral body under imaging guidance, usually fluoroscopy or CT.
With positioning of the needle confirmed, a vertebral venogram is
performed to assess the venous drainage from the vertebra. Once
satisfactory positioning of the trocar has been achieved, an opacified
methyl methacrylate is injected into the vertebrae under careful
direct flouroscopic visualization. The methyl methacrylate injection
is continued until the trabecular spaces have been filled with the
cement material. The cement hardens in 15 to 20 minutes after which
time the vertebra has been stabilized. The theorized effect of the
methyl methacrylate on the vertebral body fractures is to immobilize
microfractures which reduces any motion at the fracture level and
associated irritation of the adjacent periosteum. In addition, the
methyl methacrylate reduces stress on the remaining bone, and may
cause thermal necrosis of any nerve endings. Post-procedure care
consists of a 2-hour observation period after which time the patient
can be discharged home with follow-up on the post-procedure day.
Potential complications which can result from this procedure include
venous extravasation of the opacified cement, embolization of the
cement into the draining veins, vertebral or rib fracture, or, rarely,
infection and bleeding. The vertebral venogram is an essential part
of the procedure. It is at this time that any potential direct communication
of the vertebral veins with the epidural venous plexus or inferior
vena cava can be identified and potential inadvertent injection
of cement into the epidural venous plexus or cement pulmonary emboli
can be avoided. Fortunately, these complications are rare.
Results have been quite favorable. At present, a large multicenter
trial is under way to prospectively evaluate the procedure in a
large number of patients. However, a group of 84 patients treated
at the University of Virginia, Tampa General Hospital, and John
Hopkins Hospital between 1994 and 1997 demonstrated pain improvement
within 48 hours in 79 of the patients. Furthermore, patientís analgesic
use scale scores and mobility scale scores significantly improved
such that most patients no longer required narcotic pain medications
and were able to become ambulatory.
Potential candidates for this procedure should be seen and evaluated
by a spine surgeon. In addition, pre-procedure imaging evaluation
should include plain films, an MRI (to exclude disc extrusion or
other potential soft tissue cause for pain), and a bone scan (to
precisely localize a symptomatic level).
Percutaneous vertebroplasty has been used in the treatment of several
other disorders including metastatic disease, symptomatic hemangiomas,
and presurgical stabilization of partially compressed vertebrae.
The risk of hemorrhagic complications is somewhat increased with
the treatment of metastases and hemangiomas.
In conclusion, percutaneous vertebroplasty represents a promising
new therapy for the treatment of symptomatic osteoporotic compression
fractures as well as other lesions of the vertebrae in patients
who otherwise have few therapeutic options.