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-Howmedica-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.