Is percutaneous vertebral augmentation (vertebroplasty) effective treatment for painful vertebral fractures?

Abstract

Each year, there are approximately 750,000 new vertebral fractures in the United States (1) and 4.7 million worldwide (2). Unlike other fractures, which are usually recognized at the time of occurrence, most vertebral fractures are not recognized as discrete clinical events. Whether they are clinically recognized or not, they cause problems: height loss, spinal deformity (kyphosis, scoliosis), acute and chronic pain, restriction of thoracic and abdominal contents, impaired mobility, or disability, which in turn are associated with an increase in hospitalizations and all-cause mortality (3,4). Only 20% to 30% of vertebral fractures are diagnosed as discrete clinical events. Those that are usually present with sudden, severe back pain in the region of the fracture. The pain, which may be persistent, is typically less severe when the patient is at rest and worse when the patient is active. Management of the acute fracture episode includes conservative measures (e.g., rest, external support, treatment with analgesics or calcitonin) (5). If the pain cannot be controlled with oral analgesics, hospital admission may be required, which can be associated with substantial cost. In 1995, there were approximately 120,000 hospital admissions in the United States for vertebral fractures, and the total cost was almost $746 million (6). In comparison, the cost worldwide was estimated to be $2.4 billion (2). The pain from an acute vertebral fracture often disappears within a few days to weeks. However, even if the acute pain subsides, persistent vertebral deformity may lead to chronic pain because of paraspinal muscle spasm, degenerative arthritis in the region of the fracture, and changes in spinal alignment. The pain from the acute fracture appears to be due in part to instability (nonunion or slow union) at the fracture site. The injection of polymethylmethacrylate bone cement into collapsed vertebrae for pain relief was a logical step, and has been widely used since its introduction in France in 1987 (7) and in North America in 1997 (8). Percutaneous vertebral augmentation in the form of vertebroplasty and KyphoplastyTM has been hailed as safe and effective. Multiple levels are being treated in a single session, and some patients are actually being retreated for recurrent pain in vertebrae that were previously treated (9). With regard to safety, there is a short but considerable learning curve, in which the incidence of complications, such as fractures of the ribs or pedicles, or cement leakage leading to damage to the spinal cord or nerve roots, may approach 10%. There has been at least one death from pulmonary embolism of bone cement (10), 1 patient with a cement pulmonary embolus who was successfully treated by embolectomy (11), and another with a paradoxical cement embolus in the cerebral circulation (12). Although the procedure should not be undertaken lightly, in experienced hands, the risks seem low. In this issue of the Journal, Diamond and colleagues compared the outcomes of 55 patients who had undergone percutaneous vertebroplasty with those of 24 “controls” who declined the procedure (13). Complications were few and minor. At 24 hours, measures of pain and physical function improved dramatically in the treatment group but were unchanged in the control subjects, suggesting (but not proving) that percutaneous vertebroplasty provides effective pain relief in the short term. Length of hospital stay was reduced (9 vs. 15 days). Of interest and importance, there was no betweengroup difference in pain or physical function at 6 weeks (the first assessment after hospital discharge) and at 6 to 12 months. This is consistent with the observation that most patients with acute painful vertebral fractures improve with conservative therapy in 6 weeks or less. I applaud the authors for their efforts. There were, however, limitations to this study. The short-term improvement shown in hospitalized patients (the “tip of the iceberg”) may not apply to patients who do not require Am J Med. 2003;114:326 –328. From the University of Cincinnati Bone Health and Osteoporosis Center, University of Cincinnati College of Medicine, Cincinnati, Ohio. Requests for reprints should be addressed to Nelson B. Watts, MD, University of Cincinnati Bone Health and Osteoporosis Center, 222 Piedmont Avenue, Suite 4300, Cincinnati, Ohio 45219, or nelson. watts@uc.edu. Manuscript submitted October 28, 2002.