Polymethylmethacrylate-Augmented Screw Fixation for Stabilization of the Osteoporotic Spine : A Three-Year Follow-Up of 37 Patients

Objective : The purpose of this study was to determine the efficacy, radiological findings, clinical outcomes and complications in patients with lumbar stenosis and osteoporosis after the use of polymethyl methacrylate (PMMA) augmentation of a cannulated pedicle screw. Methods : Thirty-seven patients with degenerative spinal stenosis and osteoporosis (T-score < -2.5) underwent lumbar fusion using the Dream Technology Pedicle Screw (DTPS(TM), Dream Spine Total Solutions, Dream STS, Seoul, Korea) between 2005 and 2007. The clinical outcomes were evaluated by using the visual analog scale (VAS) and the Prolo scale. Radiologic findings were documented through computed tomography (CT) and plain films. Results : Thirty-seven patients were evaluated and included, 2 males and 35 females with an average bone mineral density (BMD) of 0.47g/cm(2). The average age of the patients was 68.7 (range, 57-88). The preoperative VAS for low back and leg pain (7.87 +/- 0.95 and 8.82 +/- 0.83) were higher as compared with postoperative VAS (2.30 +/- 1.61 and 1.42 +/- 0.73) with statistical significance (p = 0.006, p = 0.003). According to the Prolo scale, 11, 22, one and three patients were in excellent, good, fair and poor conditions, respectively. The average amount of the injected cement per one cannulated screw was 1.83 +/- 0.11 mL. Conclusion : The results show favorable outcome both clinically and radiographically for 37 patients who underwent lumbar fusion using DTPS(TM) and PMMA. Based on the results, the use of this surgical method can be a safe and effective option for the operation on the osteoporotic spine.