CHICAGO — Kyphoplasty appears associated with a low rate of complications in patients with osteoporotic or osteolytic vertebral compression fractures, according to the results of a prospective study presented at the annual meeting of the North American Spine Society.
Functional disability also improves over the long run. Such findings emerge just as use of the technique for treating vertebral compression fractures is gaining in popularity and questions about its safety and efficacy are being raised.
According to a review of the literature and complications reported to the Food and Drug Administration, the main safety concerns involve reactions to the use of acrylic (polymethylmethacrylate) bone cement, including hypotension and in some cases death, especially when multiple vertebral levels are treated in one setting. The procedure has also been linked with an increased rate of pedicle fracture and cord compression (J. Vasc. Interv. Radiol. 2004;15:1185-92).
In addition, a retrospective chart review involving 38 consecutive patients indicated that the risk of subsequent fracture in adjacent vertebrae was higher after kyphoplasty than in untreated patients, suggesting that kyphoplasty may shift stress to adjacent vertebrae (Spine 2004;29:2270-6).
In this latest prospective study, a total of 329 consecutive patients with osteoporotic or osteolytic vertebral compression fractures underwent 917 kyphoplasty procedures. Surgeries were performed at the Cleveland Clinic, said Isador Lieberman, M.D., director of its minimally invasive surgery center and center for advanced skills training, and the study's lead investigator.
The rate of subsequent compression fractures in the osteoporotic patients was 11.5%, which is almost half the natural history rate, reported Dr. Lieberman, who is one of the developers of kyphoplasty and is a paid consultant to Kyphon Inc., which manufacturers the inflatable bone tamp.
Study participants were a mean age of 69.2 years and 209 were female. All patients had painful compression fractures secondary to primary osteoporosis (228 patients), multiple myeloma (80 patients), or other malignancy (21 patients) that was refractory to nonoperative treatment.
The levels treated ranged from T3 to L5, with about half of the procedures at the thoracolumbar junction. Local anesthesia was used in 32 procedures. The average length of hospital stay was 1 day, with a range of 0.5 to 9 days.
Complications included cement leaks, which occurred in 24 patients, but none were clinically significant. One patient suffered a perioperative myocardial infarction. There were no neurologic complications or cement reactions, said Dr. Lieberman, who called the issue of such reactions as reported in the literature “misleading and erroneous.”
Short Form-36 (SF-36) health survey data pre- and post operative were available on 237 patients, with a mean of 55 weeks' follow-up.
SF-36 scores improved significantly in every category except general health, which was unchanged. Measures of physical functioning improved on a 0-to-100 scale from 22 to 36, bodily pain from 22 to 42, vitality from 31 to 41, social functioning from 38 to 61, emotional well-being from 55 to 66, and mental health from 63 to 68. “We advocate the use of kyphoplasty [as an] early intervention for osteoporotic and osteolytic vertebral compression fractures to prevent pain and progressive kyphosis,” said study investigator A. Jay Khanna, M.D.
Overall, Oswestry Disability Index scores improved from 48 to 34.3 (−13.7) and such improvements were similar for patients with osteoporosis and myeloma, (−15.8 and −14.5, respectively), said Dr. Khanna, who conducted the study at the Cleveland Clinic but is now at Johns Hopkins University in Baltimore.