Vertebral Fractures and Vertebroplasty
Did you know that 700,000 vertebral fractures occur each year in the United States? Eighty-five percent (85%) of these vertebral fractures are associated with osteoporosis. Osteoporosis primarily affects approximately 16% of women in all ethnic groups aged 50 years or more. This disease also occurs in men. Osteoporosis causes bone to lose density and strength resulting in porous, weak bones especially susceptible to fracture.
Vertebral fractures have become increasingly recognized as a cause of decline in health and, in some cases, death in an expanding elderly population.
Symptoms and Effects
Patients with osteoporotic vertebral fracture often report or exhibit various symptoms including pain, immobility, deformity (e.g. humpback) and rarely, neurologic compromise. In addition, although difficult to quantify, the negative emotional impact of vertebral fractures may be an even more important determinant of reduce quality of life.
Traditional wisdom declared that approximately two-thirds of vertebral fractures are symptom free, however this may have been underestimated. One study showed that 84% of patients with radiographically (x-ray) evident vertebral fracture reported associated back pain.
The decline in health associated with osteoporotic vertebral fractures in general is considerable. It is estimated that 6.7% of women become dependent in the basic activities of daily living because of osteoporotic vertebral fracture. The association between hip fracture and decreased survival is now well established. Up to 20% of patients die in the year following hip fracture representing a 5 to 20% reduction in expected survival. Recent studies indicate that vertebral fractures may also adversely affect survival.
Vertebral Fracture Treatment
Conventional treatment of osteoporotic vertebral fractures has been almost exclusively non-operative. Bed rest, analgesia, non-steroidal anti-inflammatory agents and physical therapy with external bracing have been the mainstays of treatment. Operative reconstruction of the spinal column has traditionally been reserved for actual or impending neurological compromise. In the elderly population this carries significant risk during surgery and hospitalization. Despite this conservative approach, or perhaps because of it, vertebral fractures in patients aged 65 years or older account for 150,000 hospital admissions in the United States each year.
The monetary cost of treating osteoporotic vertebral fracture is enormous and is likely to increase with increased longevity of the population. The number of people in the United States aged 65 or more is expected to more than double from 32 million in 1990 to 69 million in 2050. Those aged 85 years or more are expected to increase 5-fold from 3 million to 15 million. Direct medical expenses for osteoporotic fractures alone were estimated at $13.8 billion in 1995. Most of this (63%) was for treatment of hip fractures while vertebral fractures accounted for only 5%. Any changes in the treatment of vertebral fractures, particularly the use of new minimally invasive reconstruction techniques, are likely to have considerable cost implications.
The term vertebroplasty refers to percutaneous (through the skin) structural reinforcement of the vertebral body using a special cement-like substance called “polymethylmethacrylate acrylic cement” (PMMA). Dr. Galibert initially pioneered this technique in France over a decade ago for the treatment of vertebral lesions (hemangioma). Over the past 13 years the indications have been expanded to include tumors of the spine that spread (e.g. cancer) and osteoporotic vertebral collapse. The procedure was first performed in the United States for osteoporotic vertebral fracture in 1995.
Despite a small number of studies in the literature and the lack of prospective randomized trials, this procedure has gained increasing acceptance particularly as a therapy to reduce symptoms associated with tumors (e.g. cancer) that have spread to the spine. One of the reasons for this has been the universal experience of prompt relief of pain in approximately 90% of patients treated using this method.
The Procedure: Vertebroplasty
The patient is positioned horizontally (prone) on the operating table. Percutaneous vertebroplasty can be performed under either general or local anesthesia. Preventive antibiotics are used in some centers but not universally. Fluoroscopy, a special type of x-ray used during some spine procedures, is implemented to identify the vertebral pedicles and is used for needle guidance.
A special bone needle is inserted through the skin (percutaneous) and positioned. Contrast dye is injected into the vertebral body to highlight local anatomy. The cement is mixed to the consistency of thin paste and prepared for syringe injection through the needle. Fluoroscopy allows the surgeon to watch and guide the needle and cement mixture during the injection process.
After vertebral filling, the syringe and needle is withdrawn. As the cement cures (hardens) the vertebral body is stabilized. The procedure may be performed on both sides of the vertebra.
Vertebroplasty is one new procedure spine specialists may use to treat osteoporotic vertebral fractures. Vertebroplasty not only works to help stabilize spinal fractures but also helps to alleviate pain and improve the patient’s quality of life.