Temperature measurement during polymerization of polymethylmethacrylate cement used for vertebroplasty

Study Design. Ex vivo biomechanical study using osteoporotic cadaveric vertebral bodies. Objective. To measure internal vertebral body temperature during polymerization of cements used for vertebroplasty. Summary of Background Data. Previous ex vivo studies have shown that temperature increases during cement polymerization were unlikely to cause thermal necrosis. Methods. Twenty-four osteoporotic vertebral bodies were instrumented with thermocouples and injected with one of two cement volumes (6 or 10 mL) of one of two cements (Simplex P or modified Simplex P, Stryker-How-medica-Osteonics, Kalamazoo, MI). Vertebral bodies were placed in a bath (37 C) and temperatures were measured for 15 minutes from the time the cement was initially mixed. Results. In the vertebral bodies, peak temperatures at the anterior cortex ranged from 44 C to 113 C, those in the center ranged from 49 C to 112 C, and those at the spinal canal ranged from 39 C to 57 C. Dwell times at temperatures above 50 C at the anterior cortex ranged from 0 to 5.5 minutes, those in the center ranged from 0 to 8 minutes, and those at the spinal canal ranged from 0 to 2.5 minutes. Conclusion. Internal temperature elevation measured during cement polymerization was substantially higher than previously reported and may be sufficiently high to pose a risk of thermal necrosis.