The use of
bone cement to treat vertebral
compression fractures in a percutaneous manner requires placement of the cement under fluoroscopic image guidance. To enhance visualization of the flow during injection and to monitor and prevent leakage beyond the confines of the vertebral body, the orthopedic community has described increasing the amount of radiopacifier in the
bone cement. In this study, static tensile and compressive testing, as well as fully reversed
fatigue testing, was performed on three
PMMA-based
bone cements. Cements tested were SimplexP with 10%
barium sulfate (Stryker Orthopedics, Mahwah, NJ) which served as a control; SimplexP with 36%
barium sulfate prepared according to the clinical recommendation of Theodorou et al.; and KyphX HV-R with 30%
barium sulfate (Kyphon Inc., Sunnyvale, CA). Static tensile and compressive testing was performed in accordance with ASTM F451-99a.
Fatigue testing was conducted in accordance with ASTM F2118-01a under fully reversed, +/-10-, +/-15-, and +/-20-MPa stress ranges. Survival analysis was performed using three-parameter Weibull modeling techniques. KyphX HV-R was found to have comparable static mechanical properties and significantly greater
fatigue life than either of the two control materials evaluated in the present study. The static tensile and compressive strengths for all three
PMMA-based
bone cements were found to be an order of magnitude greater than the expected stress levels within a treated vertebral body. The static and
fatigue testing data collected in this study indicate that
bone cement can be designed with
barium sulfate levels sufficiently high to permit fluoroscopic visualization while retaining the overall mechanical profile of a conventional
bone cement under typical in vivo loading conditions.