Primary and secondary osteoporosis' incidence of subsequent vertebral compression fractures after kyphoplasty.

STUDY
DESIGN: Retrospective review of prospective database.
OBJECTIVES: Define the incidence of adjacent and remote fractures after kyphoplasty vertebral augmentation, and identify vulnerable subpopulations at increased risks. SUMMARY OF BACKGROUND DATA: Painful osteoporotic compression fractures can be effectively treated with methyl methacrylate vertebral augmentation, but the effect of intervention on the generation of future remote and adjacent fractures has not been identified. No paper has analyzed the association of long-term steroid use to subsequent compression fractures.
METHODS: A total of 175 patients were treated for compression fractures, from October 1999 to November 2001, 60 patients were excluded due to insufficient follow-up (less than 3 months) or malignancy related fracture. The remaining 115 patients' charts and radiographs were then individually analyzed. New fractures were identified based on changes from baseline imaging studies (). Demographic information, vertebral levels treated, adjacent fractures, and remote fractures underwent statistical analyzed (P < 0.05).
RESULTS: A total of 225 vertebral bodies were treated in 115 patients using the kyphoplasty technique; of those, 26 patients developed 34 subsequent compression fractures. The mean follow-up was 11 months (range, 3-33 months). The incidence of subsequent fracture per procedure per kyphoplasty was 15.1% (34 of 225), overall incidence per patient was 22.6% (26 of 115). There were 80 patients with primary osteoporosis and 35 patients with secondary steroid-induced osteoporosis. These populations were similar in terms of demographics, single or multiple sites, along with two or three adjacent levels treated. Seventeen of the 26 (65%) patients with subsequent fracture had secondary steroid-induced osteoporosis, while only 9 of the 26 (35%) patients had primary osteoporosis. Therefore, the incidence of post-kyphoplasty VCF in the primary osteoporotic patient was 11.25% (9 of 80) and the incidence in the steroid-induced osteoporotic patient was 48.6% (17 of 35). This increased fracture rate in the steroid-dependent patients was significant (P < 0.0001), along with adjacent fractures (12 of 19 on steroids, P = 0.0009), and remote fractures (7 of 9 on steroids, P = 0.027).
CONCLUSIONS: Steroid-induced compression fractures appear to have an increased incidence of subsequent fractures after the kyphoplasty procedure. The kyphoplasty protocol with concurrent medical osteoporotic regimen does not appear to increase, and may serve to reduce, the incidence of remote and adjacent fractures for primary osteoporotic fractures.